ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Calcification
  • Rat
  • Springer  (300)
  • MDPI Publishing
  • 1990-1994  (68)
  • 1980-1984  (213)
  • 1965-1969  (19)
Collection
Keywords
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Renal eicosanoids and blood pressure in genetically hypertensive rats of the lyon strain (1994)
    Springer
    Journal of biomedical science 1 (1994), S. 201-203 
    Details
    ISSN: 1423-0127
    Keywords: Hypertension ; Eicosanoid ; Rat ; Genetics ; Kidney
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The present paper reviews the evidence for a possible involvement of renal eicosanoids in the pathophysiology of high blood pressure in genetically hypertensive rats of the Lyon strain. Both in vivo and in vitro experiments suggest that an increased ability to synthesize the vasoconstrictor prostaglandin H2 and/or thromboxane A2 in renal vessels (1) acts as an autocrine amplifier of pressor agents and (2) may contribute to resetting the pressure natriuresis curve which is a prerequisite for the development and maintenance of hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02253302
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Noninvasive loading of the rat ulna in vivo induces a strain-related modeling response uncomplicated by trauma or periostal pressure (1994)
    Springer
    Calcified tissue international 54 (1994), S. 241-247 
    Details
    ISSN: 1432-0827
    Keywords: Loading ; Strain ; Modeling ; Rat ; Ulna
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Adaptive changes in bone modeling in response to noninvasive, cyclic axial loading of the rat ulna were compared with those using 4-point bending of the tibia. Twenty cycles daily of 4-point bending for 10 days were applied to rat tibiae through loading points 23 and 11 mm apart. Control bones received nonbending loads through loading points 11 mm apart. As woven bone was produced in both situations, any strain-related response was confounded by the response to direct periosteal pressure. Four-point bending is not, therefore, an ideal mode of loading for the investigation of strain-related adaptive modeling. The ulna's adaptive response to daily axial loading over 9 days was investigated in 30 rats. Groups 1–3 were loaded for 1200 cycles: Group 1 at 10 Hz and 20 N, Group 2 at 10 Hz and 15 N, and Group 3 at 20 Hz and 15 N. Groups 4 and 5 received 12,000 cycles of 20 N and 15 N at 10 Hz. Groups 1 and 4 showed a similar amount of new bone formation. Group 4 showed the same pattern of response but in reduced amount. The responses in Groups 2 and 3 were either small or absent. Strains were measured with single-element, miniature strain gauges bonded around the circumference of dissected bones. The 20 N loading induced peak strains of 3500–4500 μstrain. The width of the periosteal new bone response was proportional to the longitudinal strain at each point around the bone's circumference. It appears that when a bone is loaded in a normal strain distribution, an osteogenic response occurs when peak physiological strains are exceeded. In this situation the amount of new bone formed at each location is proportional to the local surface strain. Cycle numbers between 1200 and 12,000, and cycle frequencies between 10 and 20 Hz have no effect on the bone's adaptive response.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301686
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Effect of running exercise on the bone loss induced by orchidectomy in the rat (1994)
    Springer
    Calcified tissue international 55 (1994), S. 33-37 
    Details
    ISSN: 1432-0827
    Keywords: Osteoporosis ; Rat ; Orchidectomy ; Exercise ; Strength
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effect of exercise on castration-induced osteoporosis in 3-month-old male rats weighing 264±4 g at the beginning of the experiment was studied. A testosterone deficiency was induced by orchidectomy (ORC), and the exercise group ran 10 m/minute for 1 hour a day on a treadmill at 0% grade. There were seven groups of eight rats (n=56) randomized into a control group killed at time 0, and sham, ORC and ORC and exercise groups killed at 4 and 8 weeks. ORC reduced body weight gain (with analysis of variance (ANOVA) P〈0.001), and at 4 weeks the body weight was 343±14 g in ORC group and 301±4 g in the ORC and exercise group (P〈0.01). The increase in femoral length was slower in the ORC+exercise groups. The ash weight of the tibia did not decrease significantly after ORC or ORC+ exercise. ORC did not affect 45Ca incorporation, but exercise slightly increased it in the whole tibia 8 weeks after ORC (with ANOVA P=0.057). ORC had significantly lowered the trabecular bone volume in the secondary spongiosa of the distal femur at 4 and 8 weeks, and exercise did not prevent this. This is an opposite finding to our previous study with ovariectomized female rats [12]. ORC also significantly had reduced the osteoblast-lined trabecular bone surface and the number of osteoclasts by 8 weeks after the operation. Exercise increased the osteoblast-lined surface and the number of osteoclasts. The mechanical strength of the femoral neck also was reduced after ORC and this was not prevented by exercise either. In conclusion, ORC reduces bone growth and turnover which leads to osteopenia in growing rats. Moderate treadmill exercise does not reverse the ORC-induced loss of trabecular bone and the reduced mechanical strength of the femoral neck, although it has a positive effect on the osteoblast and osteoclast indices and on calcium incorporation into bone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310166
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The in vivo effect of a new, in vitro, extremely potent vitamin D3 analog KH1060 on the suppression of renal allograft rejection in the rat (1994)
    Springer
    Calcified tissue international 54 (1994), S. 150-154 
    Details
    ISSN: 1432-0827
    Keywords: Vitamin D analog ; KH1060 ; Kidney transplantation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract KH1060 is a new 20-epi-vitamin D3 analog, which has exerted a considerable immunosuppressive potency in vitro. We have tested in vivo the effect of KH1060 on the suppression of renal allograft rejection in the rat. Allogenic kidney transplantation from DA donor rats to Lewis recipient rats treated intraperitoneally with KH1060 in doses from 0.2 to 6 μg/kg/day, or saline (placebo group), or CyA 10 mg/kg/day for 10 days (positive control group), was performed. Median graft survival time in KH1060-treated groups was 7–9 days, in the placebo group 6 days, whereas CyA led to long-term graft survival, 34 days in 50% of rats and 〉100 days in 50% of rats. In vivo, KH1060 failed to prolong renal allograft survival considerably, and led to development of hypercalcemia. Our results stress the existence of a large discrepancy between the in vitro and in vivo immunoregulatory effects of this vitamin D analog.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296066
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Effect of ultrafilterable fragments from chondroitinase and protease-treated aggrecan on calcium phosphate precipitation in liposomal suspensions (1994)
    Springer
    Calcified tissue international 55 (1994), S. 176-179 
    Details
    ISSN: 1432-0827
    Keywords: Calcification ; Calcium phosphates ; Liposomes ; Mineralization ; Proteoglycans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract A liposome-centered endogenous precipitation method was used to investigate the effect of ultrafilterable fragments from the enzymatic digestion of rat chondrosarcoma aggrecan on the formation of insoluble calcium phosphate salts in buffered solutions at pH 7.4 and 22°C. Unlike the intact aggrecan and its major chondroitin sulfate and core protein components, disaccharide units from chondroitinase degradation of the aggrecan and small (〈3kg/mol molecular weight) fragments from protease digestion of the core structure were found to be only weakly inhibitory toward mineral formation. Corresponding reductions in Ca2+-binding indicate that these fragments were unable to adsorb to active sites on the apatite surface for long enough periods to significantly hinder crystal growth. The data suggest that controlled enzymatic breakdown of aggrecan may be one possible mechanism by which the calcification of growth plate cartilage is allowed to advance in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425872
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Stimulation of human osteoblast differentiation and function by ipriflavone and its metabolites (1994)
    Springer
    Calcified tissue international 55 (1994), S. 356-362 
    Details
    ISSN: 1432-0827
    Keywords: Osteoblasts ; Matrix proteins ; Collagen ; Cell differentiation ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract Ipriflavone (IP), an isoflavone derivative, has been shown to interfere with bone remodeling by inhibiting bone resorption and perhaps stimulating bone formation. In this study, we have analyzed the effect of IP and its metabolites on the differentiation and function of human osteoblastic cells. Bone marrow stromal osteoprogenitor cells (BMC) and trabecular bone osteoblasts (HOB) were isolated from human donors. The former can be induced to differentiate by treatment with dexamethasone, whereas the latter represent a more differentiated osteoblast. Incubation of BMC with metabolite III (10-5 M) for 1 week induced modest but significant changes of alkaline phosphatase activity. Though both IP and metabolite III stimulated the expression of bone sialoprotein mRNA, a protein involved in cell attachment to the matrix, only metabolite III increased the steady-state level of decorin mRNA, a collagen fibrillogenesis-regulating proteoglycan. Metabolites III and V, but not the other isoflavones, increased the expression of type I collagen mRNA in HOB, whereas no detectable changes were observed in BMC cells with any of the experimental compounds. In HOB, an increased abundance of osteopontin and bone sialoprotein mRNA were also obtained after 1-week treatment with IP or metabolite V. No appreciable effects of IP or its metabolites were seen on osteocalcin expression and synthesis by either cell type. Finally, IP consistently increased the amount of 45Ca incorporated into the cell layer by BMC, and stimulated mineralization of both BMC and HOB, assessed by von Kossa staining. Thus, IP and its metabolites regulate the differentiation and biosynthetic properties of human bone-forming cells by enhancing the expression of some important matrix proteins and facilitating the mineralization process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00299315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Effect of 1α-vitamin D3 on bone strength and composition in growing rats with and without corticosteroid treatment (1994)
    Springer
    Calcified tissue international 55 (1994), S. 443-450 
    Details
    ISSN: 1432-0827
    Keywords: Bone mechanics ; Bone composition ; Vitamin D3 ; Corticosteroid ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract The effects of 1α-vitamin D3 were studied for 6 months in 2-month-old male and female rats on a moderately low calcium diet with or without low-dose prednisolone treatment. Both cortical bone mechanical and biochemical properties were examined. Femoral bone specimens were subjected to torsional loading tests. With age, bone strength and stiffness increased in both sexes, accompanied by an increased degree of mineralization (bone ash and calcium concentrations). During growth, strength and stiffness increased more in male than in female rats. When 1α-vitamin D3 (0.5 μg/kg/day) was given alone, bone mechanical competence improved significantly whereas insulin-like growth factor-I (IGF-I) and calcium concentrations in the bone matrix were significantly reduced. Treatment with low-dose prednisolone (0.5 mg/kg/day) alone did not influence bone mechanical properties compared with intact control rats (without prednisolone) although a significant reduction in calcium concentration and an increased phosphorus concentration were measured. A combined therapy with prednisolone and 1α-vitamin D3 significantly increased bone strength, toughness, and stiffness compared with control bones. Both mineralization degree (ash and calcium concentration) and IGF-I concentration were decreased. We conclude that (1) mechanical properties of rat cortical bones improve relatively more in males compared with agematched females during growth which is related to increased bone mass and size, (2) low-dose prednisolone treatment does not change mechanical properties in males, and altered them only nonsignificantly in females despite a change in mineralization degree in both sexes; (3) treatment with 1α-vitamin D3 results in a consistent increase in mechanical competence of the bone accompanied by a significant decrease in IGF-I concentration in the bone matrix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00298558
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Expression of the α-subunit of glycoprotein hormones in the pars tuberalis-specific glandular cells in rat, mouse and guinea-pig (1994)
    Springer
    Cell & tissue research 278 (1994), S. 617-624 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Pituitary ; Pars tuberalis ; α-Subunit ; Immunocytochemistry ; In situ hybridization ; Rat ; Mouse ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The nature of the hormone(s) secreted by the pars tuberalis (PT) is still unknown. This pituitary lobe is mainly formed by specific glandular cells that differ in their ultrastructural features from the other adenohypophysial cell types. Data from the literature indicate the presence of thyroid-stimulating hormone immunoreactivity in the PT-specific cells of the rat and the Djungarian hamster but not of other species, including the mouse and guinea-pig. The PT also encloses variable numbers of pars distalis cells, essentially gonadotrophs that are mainly dispersed in its caudal area. We studied the expression of the glycoprotein hormone α-subunit in the PT of the rat, mouse and guinea-pig by in situ hybridization and immunocytochemistry. In situ hybridization, using an oligonucleotide probe complementary to rat cDNA sequence 196–237 revealed the expression of the α-subunit gene throughout the PT of the rat and the mouse; in the guinea-pig, the probe labelled no pituitary cells. Light- and electron-microscopic immunocytochemistry demonstrated α-subunit immunoreactivity in the secretory granules of the PT-specific cells in the three species examined. These cells did not react with a specific antibody against the β-subunit of luteinizing hormone, an antibody that labelled scattered gonadotrophs. The present data suggest that hormone(s) produced by the PT-specific glandular cells are, at least partly, related to glycoprotein hormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050253
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Occurrence of osteoblast necroses during ossification of long bone cortices in mouse fetuses (1994)
    Springer
    Cell & tissue research 275 (1994), S. 345-353 
    Details
    ISSN: 1432-0878
    Keywords: Osteogenesis ; Ossification ; Mineralization ; Calcification ; Cell necroses ; Mouse (NMRI)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Previous investigations concerned with in vitro osteogenesis and mineralization have revealed some indication of a participation of cell necroses in the course of calcification. These observations were confirmed by in vivo investigations on desmoid ossification in fetal mouse calvariae, where abundant necrotic osteoblasts were found at the mineralization border and in the osteoid. In the present study, ossification of long bone cortices from fetal mice was investigated by use of electron microscopy. Specimens obtained from the collection of the Institute of Anatomy, Free University of Berlin (mouse fetuses, forearm; rat fetuses, forearm) were reinvestigated for control purposes. In all cases, mineralization of osteoid was accompanied by cell necroses. Cell degeneration was characterized by swelling of the endoplasmic reticulum and loss of the plasma membrane resulting in freely distributed vesicular structures. Cell debris was incorporated within the mineral. Initially, cell necroses in the perichondrium occurred in the region surrounding the hypertrophic cartilage and the matrix of which showed spots of endochondral mineralization. Necrotic osteoblasts occurred simultaneously with mineralization of the osteoid. During further ossification of the long bone cortices, the number of necrotic cells increased markedly. In addition to necrotic cells, healthy osteoblasts, osteocytes and perichondral tissue were present, indicating that an artifact can be excluded. The importance of cell necroses in the process of mineralization is as yet unclear. Possibly, the cells act as calcium and/or phosphate stores, which are liberated by cell death to increase the amount of mineral constituents at sites of mineralization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319433
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Expression of the α-subunit of glycoprotein hormones in the pars tuberalis-specific glandular cells in rat, mouse and guinea-pig (1994)
    Springer
    Cell & tissue research 278 (1994), S. 617-624 
    Details
    ISSN: 1432-0878
    Keywords: Pituitary ; Pars tuberalis ; α-Subunit ; Immunocytochemistry ; In situ hybridization ; Rat ; Mouse ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The nature of the hormone(s) secreted by the pars tuberalis (PT) is still unknown. This pituitary lobe is mainly formed by specific glandular cells that differ in their ultrastructural features from the other adenohypophysial cell types. Data from the literature indicate the presence of thyroid-stimulating hormone immunoreactivity in the PT-specific cells of the rat and the Djungarian hamster but not of other species, including the mouse and guinea-pig. The PT also encloses variable numbers of pars distalis cells, essentially gonadotrophs that are mainly dispersed in its caudal area. We studied the expression of the glycoprotein hormone α-subunit in the PT of the rat, mouse and guinea-pig by in situ hybridization and immunocytochemistry. In situ hybridization, using an oligonucleotide probe complementary to rat cDNA sequence 196–237 revealed the expression of the α-subunit gene throughout the PT of the rat and the mouse; in the guinea-pig, the probe labelled no pituitary cells. Light-and electron-microscopic immunocytochemistry demonstrated α-subunit immunoreactivity in the secretory granules of the PT-specific cells in the three species examined. These cells did not react with a specific antibody against the β-subunit of luteinizing hormone, an antibody that labelled scattered gonadotrops. The present data suggest that hormone(s) produced by the PT-specific glandular cells are, at least partly, related to glycoprotein hormones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331382
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    The immunolocalization of small nuclear ribonucleoprotein particles in testicular cells during the cycle of the seminiferous epithelium of the adult rat (1994)
    Springer
    Cell & tissue research 278 (1994), S. 363-378 
    Details
    ISSN: 1432-0878
    Keywords: Key words: snRNPs ; Testis ; Spermatocytes ; Spermatids ; Immunocytochemistry ; Chromatoid body ; Intermitochondrial nuage ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The objective of this study was to determine the cellular and subcellular distribution of small nuclear ribonucleoprotein particles (snRNPs) in the adult rat testis in relation to the different cell types at the various stages of the cycle of the seminiferous epithelium. The distribution of snRNPs in the nucleus and cytoplasm of germ cells was quantitated in an attempt to correlate RNA processing with morphological and functional changes occurring during the development of these cells. Light-microscopic immunoperoxidase staining of rat testes with polyclonal anti-Sm and monoclonal anti-Y12 antibodies localized spliceosome snRNPs in the nuclei and cytoplasm of germ cells up to step 10 spermatids. Nuclear staining was intense in Sertoli cells, spermatogonia, spermatocytes, and in the early steps of round spermatid development. Although comparatively weaker, cytoplasmic staining for snRNPs was strongest in mid and late pachytene spermatocytes and early round spermatids. Quantitative electron-microscopic immunogold labeling of Lowicryl embedded testicular sections confirmed the light-microscopic observations but additionally showed that the snRNP content peaked in the cytoplasm of mid-pachytene spermatocytes and in the nuclei of late pachytene spermatocytes. The immunogold label tended to aggregate into distinct loci over the nuclear chromatin. The chromatoid body of spermatids and spermatocytes and the finely granular material in the interstices of mitochondrial aggregates of spermatocytes were found to be additional sites of snRNP localization and were intensely labeled. This colocalization suggests that these dense cytoplasmic structures may be functionally related. Anti-U1 snRNP antibodies applied to frozen sections showed the same LM localization pattern as spliceosome snRNPs. Anti-U3 snRNP antibodies applied to frozen sections stained nucleoli of germ cells where pre-rRNA is spliced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414179
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Selective association of nerve fibres immunoreactive for substance P or bombesin with putative cholinergic neurons of the male rat major pelvic ganglion (1994)
    Springer
    Cell & tissue research 278 (1994), S. 589-594 
    Details
    ISSN: 1432-0878
    Keywords: Autonomic ganglia ; Neuropeptides ; Pelvic plexus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The male rat major pelvic ganglion contains both sympathetic and parasympathetic neurons that supply the lower urinary and digestive tracts, and the reproductive organs. The aim of this study was to describe the distribution and identify potential targets of sensory and intestinofugal axons in this ganglion. Two putative markers of these projections were chosen, substance P for primary sensory axons and bombesin for myenteric intestinofugal projections. Varicose substance P-immunoreactive axons were associated only with non-noradrenergic (putative cholinergic) somata, and most commonly with those that contained vasoactive intestinal peptide. Immunoreactivity for substance P was also present in a small group of non-noradrenergic somata, many of which were immunoreactive for enkephalins, neuropeptide Y or vasoactive intestinal peptide. Bombesin immunoreactivity was found only in preterminal and terminal (varicose) axons, the latter of which were exclusively associated with non-noradrenergic somata that contain neuropeptide Y-immunoreactivity. Some varicose axons containing either substance P-or bombesin-immunoreactivity were intermingled with clumps of small, intensely fluorescent cells. These studies indicate that substance P-and bombesin-immunoreactive axons are likely to connect with numerically small, but discrete, populations of pelvic neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00331378
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Zona glomerulosa of the adrenal gland in a transgenic strain of rat: a morphologic and functional study (1994)
    Springer
    Cell & tissue research 278 (1994), S. 21-28 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Adrenal cortex ; Renin-angiotensin system ; Steroidogenesis ; Electron microscopy ; Morphometry ; Rat ; transgenic (mRen2) 27
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Transgenic rats for the murine Ren-2 gene display high blood pressure, low circulating levels of angiotensin II, and high renin content in the adrenal glands. Moreover, transgenic rats possess an increased aldosterone secretion (maximal from 6 to 18 weeks of age), paralleling the development of hypertension. To investigate further the cytophysiology of the adrenal glands of this strain of rats, we performed a combined morphometric and functional study of the zona glomerulosa of 10-week-old female transgenic rats. Morphometry did not reveal notable differences between zona glomerulosa cells of transgenic and age- and sex-matched Sprague-Dawley rats, with the exception of a marked accumulation of lipid droplets, in which cholesterol and cholesterol esters are stored. The volume of the lipid-droplet compartment underwent a significant decrease when transgenic rats were previously injected with angiotensin II or ACTH. Dispersed zona glomerulosa cells of transgenic rats showed a significantly higher basal aldosterone secretion, but their response to angiotensin II and ACTH was similar to that of Sprague-Dawley animals. Angiotensin II-receptor number and affinity were not dissimilar in zona glomerulosa cells of transgenic and Sprague-Dawley rats. These data suggest that the sustained stimulation of the adrenal renin-angiotensin system in transgenic animals causes an increase in the accumulation in zona glomerulosa cells of cholesterol available for steroidogenesis, as indicated by the expanded volume of the lipid-droplet compartment and the elevated basal steroidogenesis. However, the basal hyperfunction of the zona glomerulosa in transgenic animals does not appear to be coupled with an enhanced responsivity to its main secretagogues, at least in terms of aldosterone secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305774
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    The immunolocalization of small nuclear ribonucleoprotein particles in testicular cells during the cycle of the seminiferous epithelium of the adult rat (1994)
    Springer
    Cell & tissue research 278 (1994), S. 363-378 
    Details
    ISSN: 1432-0878
    Keywords: snRNPs ; Testis ; Spermatocytes ; Spermatids ; Immunocytochemistry ; Chromatoid body ; Intermitochondrial nuage ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The objective of this study was to determine the cellular and subcellular distribution of small nuclear ribonucleoprotein particles (snRNPs) in the adult rat testis in relation to the different cell types at the various stages of the cycle of the seminiferous epithelium. The distribution of snRNPs in the nucleus and cytoplasm of germ cells was quantitated in an attempt to correlate RNA processing with morphological and functional changes occurring during the development of these cells. Light-microscopic immunoperoxidase staining of rat testes with polyclonal anti-Sm and monoclonal anti-Y12 antibodies localized spliceosome snRNPs in the nuclei and cytoplasm of germ cells up to step 10 spermatids. Nuclear staining was intense in Sertoli cells, spermatogonia, spermatocytes, and in the early steps of round spermatid development. Although comparatively weaker, cytoplasmic staining for snRNPs was strongest in mid and late pachytene spermatocytes and early round spermatids. Quantitative electron-microscopic immunogold labeling of Lowicryl embedded testicular sections confirmed the light-microscopic observations but additionally showed that the snRNP content peaked in the cytoplasm of midpachytene spermatocytes and in the nuclei of late pachytene spermatocytes. The immunogold label tended to aggregate into distinct loci over the nuclear chromatin. The chromatoid body of spermatids and spermatocytes and the finely granular material in the interstices of mitochondrial aggregates of spermatocytes were found to be additional sites of snRNP localization and were intensely labeled. This colocalization suggests that these dense cytoplasmic structures may be functionally related. Anti-U1 snRNP antibodies applied to frozen sections showed the same LM localization pattern as spliceosome snRNPs. Anti-U3 snRNP antibodies applied to frozen sections stained nucleoli of germ cells where pre-rRNA is spliced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414179
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Calcified structures and calcification in protists (1994)
    Springer
    Protoplasma 181 (1994), S. 78-105 
    Details
    ISSN: 1615-6102
    Keywords: Calcification ; Coccolithophorids ; Coccolithogenesis ; Foraminifera ; Protists ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The diversity of calcified structures found in protists, the mechanisms utilized to form these structures, and the role these structures play in the taxonomy and systematics of the protists are presented. The two most frequently studied orders of protists which produce calcified structures, the coccolithophorids and foraminifera, are featured. However, consideration is given to the less known and least studied organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01666390
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    The role of extracellular calcium in pregnancy-induced attenuation of phenylephrine contraction in rat aorta with functional endothelium (1994)
    Springer
    Journal of comparative physiology 164 (1994), S. 81-87 
    Details
    ISSN: 1432-136X
    Keywords: Vascular smooth muscle ; Phenylephrine-induced contraction ; Pregnancy ; Aorta ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The effect of pregnancy on the supply of calcium ions for the contractile responses of rat aortic rings to phenylephrine was investigated. The contractility of intact aortic rings from pregnant rats, compared with that of similar rings from non-pregnant rats, to phenylephrine and potassium chloride was significantly decreased. Contractions of rings from non-pregnant rats, pretreated with phenylephrine or potassium chloride, in response to calcium chloride were greater than those of similarly treated rings from pregnant rats. When the concentration of calcium chloride in the medium bathing the rings was reduced to 0.8 mmol·l-1, the contractile response to phenylephrine was significantly (P〈0.005) inhibited in rings from both pregnant and non-pregnant rats but to a greater extent in rings from non-pregnant rats. Contractions of aortic rings from pregnant rats in response to phenylephrine in calcium-free medium were similar to those of rings from non-pregnant rats, suggesting equal dependence on calcium from intracellular stores. The results suggest that pregnancy decreased the response to calcium influx into the aortic smooth muscle cells through both receptor-and voltage-operated calcium entry pathways. Since de-endothelialisation reversed the pregnancy-induced diminished contraction to phenylephrine, it is likely that pregnancy interferred with contractions induced by activation of receptors with phenylephrine through enhanced production of endothelium-derived relaxing factor(s).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00714575
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Postprandial thermogenesis of rats with glutamate induced obesity in relation to energy intake (1993)
    Springer
    European journal of nutrition 32 (1993), S. 71-73 
    Details
    ISSN: 1436-6215
    Keywords: Rat ; glutamate-induced obesity ; postprandial thermogenesis ; Ratte ; Glutamat-induzierte Adipositas ; postprandiale Thermogenese
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Bei 4 Monate alten Ratten mit Glutamat-induzierter Adipositas wurde die postprandiale Thermogenese über 8 h nach Fütterung von 300, 450 und 600 kJ/kg0,75 einer Pellet-Diät mittels indirekter Kalorimetrie in computergesteuerten Stoffwechselkäfigen mit offenem Kreislauf bestimmt. Bei den adipösen Tieren war die postprandiale Thermogenese nach Aufnahme von 600 kJ/kg0,75 (oberhalb des Energieerhaltungsbedarfs) signifikant auf 40% der Thermogenese der Kontrolltiere reduziert (12,0 gegenüber 31,5 kJ/kg0,75×8 h). Es wird geschlußfolgert, daß die Ratte mit Glutamat-induzierter Adipositas als ein Tiermodell mit beeinträchtigter fakultativer Thermogenese anzusehen ist, die hauptsächlich durch eine Verminderung der sympathischen adrenergen Aktivität verursacht ist.
    Notes: Summary Postprandial thermogenesis was estimated in 4-month-old male rats with glutamate induced obesity after being fed with 300, 450 and 600 kJ/kg0.75 of a pellet diet, respectively by indirect calorimetry in computer-controlled open circuit metabolic cages over 8 h. After an intake of 600 kJ/kg0.75 (above the maintenance energy requirement) postprandial thermogenesis was significantly reduced in the obese animals to about 40% of control rats (12.0 versus 31.5 kJ/kg0.75×8 h). It is concluded that the glutamate obese rat can be accepted as an animal model with impaired facultative thermogenesis, mainly caused by a reduction of sympathetic adrenergic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01610087
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Colocalization of cholesterol and hydroxyapatite in human atherosclerotic lesions (1993)
    Springer
    Calcified tissue international 52 (1993), S. 94-98 
    Details
    ISSN: 1432-0827
    Keywords: Atherosclerosis ; Calcification ; Hydroxyapatite ; Cholesterol ; Filipin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Cholesterol and calcium phosphate, the latter in the form of hydroxyapatite, accumulate in atherosclerotic lesions. In this report, we demonstrate that these organic and inorganic constitutents of lesions can accumulate together, closely associated in crystal agglomerates. Using the fluorescent cholesterol probe, filipin, we identified unesterified cholesterol that was associated with calcium granules in tissue sections of lesions. We also have shown that small crystallites of cholesterol can associate with preformed hydroxyapatite crystals in vitro. Scanning electron microscopy couple with energy-dispersive X-ray analysis demonstrated the physical association of many small crystallites of cholesterol with larger crystals of hydroxyapatite. These small crystallites of cholesterol associated with hydroxyapatite stained with filipin. This contrasted with the lack of filipin staining of unassociated larger cholesterol crystals or hydroxyapatite alone. How cholesterol and calcium come to be closely associated in crystal agglomerates within atherosclerotic lesions remains to be determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00308315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Sustained release of salmon calcitonin in vivo from lactide: Glycolide copolymer depots (1993)
    Springer
    Calcified tissue international 52 (1993), S. 361-364 
    Details
    ISSN: 1432-0827
    Keywords: Calcitonin ; Sustained release ; Copolymer depot ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Studies were carried out to determine whether monolithic depot formulations, prepared using lactide:glycolide copolymers, could be used to administer salmon calcitonin (sCT) to rats in vivo. Formulations containing 2, 5, or 10% (w/w) sCT were administered subcutaneously to female Wistar strain rats. Release of sCT was determined by measurement of peptide in plasma using a specific radioimmunoassay and by measurement of residual sCT in the depots after recovery at postmortem. Plasma calcium concentrations and cumulative weight gain of the animals were used to measure pharmacological effects of the released sCT. Release of sCT from the depots was controlled by the copolymer and was sustained for periods up to 10 days. However, the release of sCT from the depots did not significantly alter plasma calcium concentrations, and effects on cumulative weight gain were small and transient. Peptide loading of the formulations was shown to modify sCT release. Maximal release of sCT from depots containing 10% peptide occurred over a 7 to 14-day period postadministration, with 5% sCT release occurred between days 11 and 14, and with 2% sCT, the period of maximal release was between days 11 and 18. Release of peptide from the depots was essentially complete by 21 days postadministration irrespective of the peptide loading. These data suggest that lactide:glycolide copolymer depots may have application for the convenient clinical administration of sCT in metabolic bone diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310200
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Mechanical properties, bone mineral content, and bone composition (collagen, osteocalcin, IGF-I) of the rat femur: Influence of ovariectomy and nandrolone decanoate (anabolic steroid) treatment (1993)
    Springer
    Calcified tissue international 53 (1993), S. 269-277 
    Details
    ISSN: 1432-0827
    Keywords: Bone ; Nandrolone decanoate ; Ovariectomy ; Bone mechanics ; IGF-I ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Nandrolone decanoate (ND) is an anabolic steroid with a positive effect on bone mass in osteoporotic patients. The mechanism of action, (i.e., reduction of bone resorption and/or Stimulation of bone formation), the ultimate effect on mechanical properties, and the most effective dosage are not yet clear. To address these issues, dose-related effects of the long-term effect of ND on Serum and bone biochemistry, bone mineral content, and bone mechanical properties in ovariectomized (OVX) rats (12 weeks old at the Start of the experiment) were Studied for 6 months. The results were compared with those obtained in agematched, intact, and OVX rats. OVX caused in the femur a significant increase in net periosteal bone formation and net endosteal bone resorption of bone collagen content and torsional strength, and of Serum alkaline phosphatase, osteocalcin, and insulin-like growth factor-I (IGF-I) levels, whereas cortical bone density and calcium/creatinine and phosphorus/creatinine in 24-hour urine were Significantly reduced. Treatment of OVX rats with 1 mg ND/14 days resulted in a Significant increase in periosteal bone formation, femur length, cortical and trabecular bone mineral content and density, torsion stiffness and Strength, and bone IGF-I content, and a decrease in Serum osteocalcin, urinary calcium/creatinine levels, and bone collagen content compared with OVX controls. The higher ND dosage of 2.5 mg/14 days did not improve the results. ND treatment did not reverse all changes induced by OVX to the level of the intact controls. These results indicate that ND acts as an antiresorptive drug and as a bone formation Stimulating drug. Furthermore, the increased bone mass and bone mineral density is associated with improved bone Strength and stiffness and the presence of an increased amount of IGF-I. IGF-I is a growth factor considered to play a role in the maintenance of normal skeletal balance by a paracrine or autocrine mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320913
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    The effects of the aminobisphosphonate alendronate on thyroid hormone-induced osteopenia in rats (1993)
    Springer
    Calcified tissue international 53 (1993), S. 278-282 
    Details
    ISSN: 1432-0827
    Keywords: Hyperthyroidism ; Osteopenia ; Bisphosphonate ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Hyperthyroidism, either endogenous or iatrogenic, leads to increased bone turnover and osteopenia. This study was conducted to examine (1) whether thyroid hormone excess in rats causes bone changes similar to those seen in patients with hyperthyroidism, and (2) the effects of the aminobisphosphonate alendronate on the thyroid hormone-induced bone changes. Sprague-Dawley male rats, divided into four groups, received L-thyroxine (T4) 250 μg/kg/day (+T4) or vehicle (-T4) subcutaneously six times per week and alendronate 1.75 mg/kg (+ALN) or vehicle (-ALN) orally twice a week. Rats were sacrificed after 3 weeks of treatment, blood samples were analyzed for serum T4, triiodo-L-thyronine (T3), and osteocalcin, and the proximal tibiae were processed for histomorphometric analysis. Serum T4 and T3 levels measured 20–24 hours after the last injection were 2 to 2.5-fold higher in +T4 groups than in-T4 groups. Serum osteocalcin was significantly (P 〈 0.05) higher in +T4/-ALN group than in the other groups, which were not statistically different from each other. T4 treatment (+T4/-ALN) significantly decreased the amount of cancellous bone volume (-45%) and increased osteoid surface (+254%), osteoblast surface (+111%), and osteoclast surface (+176%) relative to control values. Alendronate increased the bone volume above control values in both T4-treated (+ T4/ +ALN) and untreated (-T4/ +ALN) rats, and prevented the T4-induced increase in bone turnover in +T4/+ALN rats. It is concluded that (1) excess thyroid hormone induces cancellous bone loss associated with high bone turnover in the rat, and (2) this bone loss can be prevented by alendronate through the inhibition of osteoclastic activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320914
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    An experimental model of ascending pyelonephritis due toCandida albicans in rats (1993)
    Springer
    Mycopathologia 123 (1993), S. 149-154 
    Details
    ISSN: 1573-0832
    Keywords: Ascending pyelonephritis ; Candida albicans ; Experimental model ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We developed a new experimental model of ascendingCandida pyelonephritis in female rats with leukopenia and vesicoureteral reflux. Rats were treated transperitoneally with cyclophosphamide (200 mg/kg) to induce leukopenia 3 days before and transurethrally with diluted acetic acid solution to induce vesicoureteral reflux 1 day before inoculation ofCandida albicans strain, ATCC 10259 (containing 107 cells). Microscopy revealed acute pyelonephritis in whichCandida cells invaded from the fornix and/or papilla into the medulla within 3 days after inoculation. Between 7 and 28 days after inoculation, chronic pyelonephritis reached the cortex. The incidence of pyelonephritis increased gradually and was approximately 80% after 7 days.Candida colony counts of bladder urine specimens obtained by direct puncture were significantly greater in rats with pyelonephritis extending into the parenchyma than in those with pyelonephritis located along the pelvis (p〈0.01). These results suggest that this rat model shows the characteristic feature of ascending pyelonephritis due toC. albicans and that the severity ofCandida pyelonephritis can be estimated fromCandida counts of bladder urine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01111265
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Yeast single copy gene URP1 is a homolog of rat ribosomal protein gene L21 (1993)
    Springer
    Current genetics 23 (1993), S. 15-18 
    Details
    ISSN: 1432-0983
    Keywords: Yeast ; Rat ; Ribosomal protein ; 60S Ribosomal subunit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary This communication reports on a single-copy gene of Saccharomyces cerevisiae which is homologous to the rat ribosomal protein gene L21. The yeast and the rat genes show 59% identity in DNA sequences and in the predicted protein sequences. This yeast gene is, therefore, assumed to code for an as yet unassigned ribosomal protein (URP1). The URP1 open reading frame is 480 nucleotides long and can encode a protein of about Mr 18 200. Like most of the other known ribosomal protein genes, URP1 is interrupted by an intron in its 5′ terminal part and it is preceeded by upstream sequence elements which usually regulate transcription of these genes. Northern blot analysis reveals that the URP1 gene is actually expressed in vivo.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00336743
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Neurofilaments in rat and cat spinal cord; a comparative immunocytochemical study of phosphorylated and non-phosphorylated subunits (1993)
    Springer
    Cell & tissue research 272 (1993), S. 249-256 
    Details
    ISSN: 1432-0878
    Keywords: Spinal cord ; Motoneurones ; Dorsal horn ; Neurofilament ; Phosphorylation ; Immunocytochemistry ; Rat ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Neurofilament immunoreactivity was examined in spinal cords of rats and cats with antibodies to all three subunits (68 kD, 155 kD and 200 kD) and to different phosphorylation states of 200 kD. NFHP-, an antibody against non-phosphorylated 200 kD, labelled all rat neuronal perikarya but failed to labet cat neurofilaments. In both species, the perikarya and processes of motoneurones were immunoreactive for all three subunits but most dorsal horn neuronal perikarya were not immunoreactive for 68 kD and 155 kD. Motoneuronal perikarya and proximal processes showed filamentous labelling for 68 kD but not for 155 kD in the rat, while in neither species did these show labelling with RT97, an antibody against a highly phosphorylated form of 200 kD; immunoreactivity for 200 kD was present in both filamentous (probably partially phosphorylated) and non-filamentous (non-phosphorylated) forms, but in dorsal horn neurones only the latter was present. Interpretations consistent with this data are: in rat and possibly also cat, motoneuronal neurofilaments consist of a 68 kD backbone with partially phosphorylated 200 kD sidearms, with both 155 kD and 200 kD (non-phosphorylated) subunits in a non-filamentous form; this neurofilament becomes more highly phosphorylated along the proximal processes. The dorsal horn neurones probably contain 200 kD in a non-filamentous form but may lack the other subunits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302730
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Microliths in normal salivary glands of cat investigated by light and electron microscopy (1993)
    Springer
    Cell & tissue research 272 (1993), S. 321-327 
    Details
    ISSN: 1432-0878
    Keywords: Calcification ; Calcinosis ; Calculi ; Microliths ; Salivary gland calculi ; Salivary glands ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract This investigation concerns the natural history of microlith in the salivary glands of cat. Microliths were detected in more sublingual than submandibular glands and were almost absent in the parotid. They were found intraparenchymally, intraluminally and interstitially, and ultrastructurally in phagosomes of acinar, ductal and myoepithelial cells, intermixed with the cytoplasm of degenerate acinar cells, and in intraparenchymal macrophages and a multinuclear giant cell. They appear to form in healthy acinar cells during autophagocytosis, and possibly to be discharged luminally, laterally or basally, and to form in the debris of degenerate cells intraparenchymally and intraluminally. They appear to be removed by expulsion in the saliva, scavenging macrophages, and possible eventual degradation in the parenchymal phagosomes. The greater occurrence of microliths in the sublingual gland may relate to a low level of secretory activity, and the near absence of microliths in the parotid to a low level of calcium. The feline salivary glands were found to be an outstanding model for the investigation of microlithiasis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302737
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Confocal laser scanning light microscopy of the extra-thecal epithelia of undecalcified scleractinian corals (1993)
    Springer
    Cell & tissue research 272 (1993), S. 533-543 
    Details
    ISSN: 1432-0878
    Keywords: Mucocytes ; Calcification ; Intercellular spaces ; Zooxanthellae ; Calicoblastic ectoderm ; Confocal laser scanning microscopy ; Freeze-substitution ; Corals: Galaxea fascicularis, Acropora formosa, Tubastrea faulkneri (Cnidaria)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The extra-thecal epithelia of cryofixed undecalcified, freeze-substituted polyps of the scleractinian corals Galaxea fascicularis and Tubastrea faulkneri and axial and basal polyps of Acropora formosa have been examined, in anhydrously prepared thick slices, by confocal laser scanning light microscopy. The avoidance of chemical fixation and decalcification makes it possible to determine whether previously seen structures are real or artefactual products of swelling, shrinkage and distortion. All of the epithelia of all the corals examined are characterised by well defined intercellular spaces. Mucocytes are present in all cell layers in Galaxea and Tubastrea but are not present in any cell layers in the axial polyp of Acropora although they are abundant in the oral ectoderm of the basal polyps in this coral. Zooxanthellae are absent in Tubastrea, the epithelia of the exert septa of Galaxea and the axial polyp of Acropora. The calicoblastic ectoderm is generally composed of thin squamous cells with large intercellular spaces. At rapidly calcifying regions such as the tips of the exert septa of Galaxea, the calicoblastic cells are elongated with extensive arborisation of the basal regions of the cells. They are separated by large intercellular spaces and contain numerous fluorescent granules. The apical regions of these cells appear to be closely applied to the surface of the skeleton. There is no evidence of a space between the apical region of the calicoblastic cells and the skeleton.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318560
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Immunohistochemical localization of insulin-like growth factor 1 and 2 in the endocrine pancreas of rat, dog, and man, and their coexistence with classical islet hormones (1993)
    Springer
    Cell & tissue research 273 (1993), S. 249-259 
    Details
    ISSN: 1432-0878
    Keywords: Endocrine pancreas ; IGF-1 ; IGF-2 ; Insulin ; Glucagon ; Somatostatin ; Pancreatic polypeptide ; Man ; Dog ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunohistochemical techniques were used to study the occurrence and distribution of insulin-like growth factor 1 (IGF-1) and IGF-2 in the pancreas of man, dog, and rat and their possible coexistence with insulin (INS), glucagon (GLUC), somatostatin (SOM) and pancreatic polypeptide (PP). All control experiments, including pre-absorption of the antisera with synthetic peptide hormones, indicated the specificity of the immunoreactions obtained. In all species investigated, IGF-2-immunoreactivity occurred exclusively in INS-immunoreactive cells as was found by the use of consecutive sections and double immunofluorescence on identical sections. In contrast, IGF-1-immunoreactivity co-existed with GLUC-immunoreactivity. In man, singular SOM-immunoreactive cells also contained IGF-1-immunoreactivity. Thus, IGF-1 and IGF-2 can be localized by means of immunohistochemistry in the mammalian pancreas, and can be shown to occur in different islet cell populations. It is presumed that IGF-1 derived from A-cells and/or D-cells acts on the B-cells in a paracrine manner. The co-existence of IGF-2-immunoreactivity and INS-immunoreactivity in the human, rat, and dog endocrine pancreas indicates that mammalian IGF-2 and INS genes are regulated simultaneously.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312826
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Atrial natriuretic peptide binding in rat placenta, yolk sac, decidua, and materal placental vessels (1993)
    Springer
    Cell & tissue research 272 (1993), S. 391-394 
    Details
    ISSN: 1432-0878
    Keywords: ANP binding ; Yolk sac ; Decidua ; Maternal placental vessels ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Using in vitro autoradiography, binding sites of 125I-ANP (atrial natriuretic peptide) were localized in the rat placenta, visceral yolk sac, and decidua at 16, 18, and 20 days of gestation. There was diffuse binding over the labyrinthine region of the placenta and an intense binding over the decidual gland and visceral yolk sac. In the yolk sac, ANP localized over the cores of the villi where it may be involved with the regulation of transport across the membranes or the flow of blood through the vitelline vessels. Of particular interest was binding over the maternal blood vessels supplying the decidual region and placenta. Receptors were located on the endothelial cells and smooth muscle cells of the arteries and veins, indicating that ANP may be involved with regional regulation of blood flow to the placenta.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302744
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Seasonal localization of a collagenous protein in the organic matrix of spicules from the gorgonian Leptogorgia virgulata (Cnidaria: Gorgonacea) (1993)
    Springer
    Cell & tissue research 273 (1993), S. 309-316 
    Details
    ISSN: 1432-0878
    Keywords: Spicule ; Calcification ; Organic matrix ; Collagen ; Leptogorgia virgulata (Cnidaria)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Spicules of the gorgonian Leptogorgia virgulata possess an insoluble matrix fraction that is predominantly collagenous in summer months. This collagenous component is largely absent in winter months. Using an antibody directed against the 140 kD collagenous protein (CP) of the insoluble matrix, immuno-gold labelling was employed to localized this protein at the transmission electron-microscopy level throughout the year, and in different areas of the gorgonian colonies. Within the tip regions, the 140 kD CP varied throughout the year in the spicules, electron-dense bodies (EDBs) of scleroblasts, polyp vesicles, desmocytes and axes. In the mid and base regions, the 140 kD CP varied throughout the year in the spicules, EDBs and lysosomes of scleroblasts, desmocytes and axes. This variation in the location and density of the label suggests a dynamic annual cycling of the collagenous component of the insoluble matrix. EDBs may transport a collagenous component of the matrix to the spicule-forming vacuole. A component of the 140 kD CP may be transported and/or degraded by polyp vesicles and lysosomes, respectively. The pattern of labelling of the axial region suggests that translocation and storage of a component of the collagenous protein may occur. Environmental factors may be responsible for the triggering of matrix cycling.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312833
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    A monoclonal antibody disrupting cell-cell adhesion of rat ascites hepatoma cells (1993)
    Springer
    Cell & tissue research 273 (1993), S. 363-370 
    Details
    ISSN: 1432-0878
    Keywords: Ascites hepatoma ; Adhesive factor ; Monoclonal antibody ; Cell membrane polarity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract A cell surface-associated adhesive factor (AF) separated from differentiated rat ascites hepatoma AH136B cells (forming cell islands in vivo) has been highly purified by chromatography. AF is assumed to mediate the cell-cell adhesion essential to island formation of the hepatoma cells. A substance, immunologically crossreactive with AF, is present in the ascites fluid or culture medium of the AH136B cells. Because the substance is almost identical to AF in molecular weight and aggregation-promoting activity, it has been concluded that AF is released into the ascites fluid where it is concentrated. Monoclonal antibodies have been raised against AF purified from ascites fluid of AH136B cells. We have obtained a monoclonal antibody, coded MoAF-6D6, that strongly abolishes the aggregation-promoting activity of AF. When AH136B cell islands are incubated in the presence of Fab fragments of MoAF-6D6, cell detachment from the islands is evident within 24 h. Cell islands following 36-h culture show a distinct dissociation and islands completely lose their organization 48 h after culture. The dissociating effect of MoAF-6D6 is neutralized by the addition of AF. These results suggest that AF plays a significant role in the maintenance of cell islands.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00312839
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Doppler radar device as a useful tool to quantify the liveliness of the experimental animal (1993)
    Springer
    Medical & biological engineering & computing 31 (1993), S. 340-342 
    Details
    ISSN: 1741-0444
    Keywords: Doppler radar ; Liveliness ; Motion quantifier ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract The Doppler radar device which is described here is shown to be a reliable and accurate device to quantify the liveliness of an experimental rat. During recording the animal did not seem to be disturbed in any way by the device. It could stay in its normal cage, move freely, walk around and eat and drink ad libitum. Measurement did not require extra light, sound or other stimuli. Interpretation of the data was easy. The computer which samples the Doppler radar output signal generates activity curves which were easily interpreted for different ranges of vitality, varying between high liveliness and apnoea or cardiac arrest. The apparatus is low priced, and simple to build and use.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02446685
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Verapamil induces increased bone volume and osteopenia in female rats but has the opposite effect in male rats (1992)
    Springer
    Calcified tissue international 50 (1992), S. 524-526 
    Details
    ISSN: 1432-0827
    Keywords: Verapamil ; Bone ; Osteopenia ; Rat ; Female ; Intestinal calcium absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Verapamil inhibits the intestinal absorption of calcium (Ca) and increases serum parathyroid hormone in rats. The effects of verapamil on bone tissue after long-term treatment is, however, not well described. Adult female and male Sprague-Dawley rats received verapamil in their drinking water at a dosage of 0.075 mg/ml (low dose) or 0.75 mg/ml (high dose) for 12 weeks; control rats received only drinking water. All rats were fed a diet containing 0.1% Ca and 0.5% P. In female rats, the amount of bone ash per volume was significantly reduced from 0.742 g/ml in controls to 0.713 g/ml after low-dose treatment of verapamil, and to 0.667 g/ml following high-dose treatment (P〈0.01). The tibial length was increased from 39.7 mm in controls to 40.3 mm or to 40.7 mm after low or high doses (P〈0.01). The tibial volume increased from 0.385 ml in controls to 0.397 ml after low doses and to 0.429 ml after high doses (P〈0.01). In contrast, in male rats the amount of bone ash per volume was significantly increased from 0.578 g/ml in controls to 0.580 g/ml after low doses and to 0.620 g/ml after high doses of verapamil (P〈0.01). The tibial bone volume in males as decreased from 0.633 ml in controls to 0.641 ml after low doses and to 0.583 ml after high doses (P〈0.05). The tibial length in the males was not changed by verapamil. The intestinal absorption of Ca was reduced in male rats from 5.28 in controls to 4.03 (serosa/mucosa) after low-dose treatment and to 2.46 after high-dose treatment with verapamil (P〈0.05). In female rats, the intestinal absorption of Ca did not change after verapamil treatment. Thus, chronic treatment with verapamil in female rats induced osteopenia whereas in male rats bone growth was inhibited.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582167
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Induction of normal and dystrophic mineralization by glycerophosphates in long-term bone organ culture (1992)
    Springer
    Calcified tissue international 50 (1992), S. 553-563 
    Details
    ISSN: 1432-0827
    Keywords: Mineralization ; Calcification ; Dystrophic calcification ; Bone organ culture ; Chick embryo
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The effectiveness of Na-β-, and Ca-glycerophosphates (GPs) in inducing mineralization was tested during long-term organ culture of femurs from 14-day-old chick embryos. When bones were incubated with Na-GP, a 66% rise in inorganic phosphate level was measured in the medium, supporting the notion that provision of a substrate for alkaline phosphatase (ALP) increased available phosphate. On the other hand, if the concentrations of Ca2+ were raised, available inorganic phosphate was decreased. Similarly, increases in inorganic phosphate decreased available calcium. Both GPs induced mineralization in bone and cartilage, but more matrix was mineralized with Ca-GP. However, the induction of mineralization by GPs was accompanied by dystrophic calcification, reduction of matrix formation and ALP activity, and increased release of lactate dehydrogenase into the culture medium. The new osteoid, which formed during culture, mineralized in the absence of GPs without the above adverse effects provided the culture period was longer than 15 days. The described organ culture system therefore facilitates studies of the mechanism of bone mineralization without the disadvantages of GP addition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582172
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Liposome interactions with hydroxyapatite crystals: A possible mechanism in the calcification of atherosclerotic plaques (1992)
    Springer
    Calcified tissue international 50 (1992), S. 261-265 
    Details
    ISSN: 1432-0827
    Keywords: Liposomes ; Hydroxyapatite ; Aggregation ; Atherosclerosis ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Some stages in the calcification of atherosclerotic plaques may involve associations between lipids and hydroxyapatite (HA) by surface interactions. Liposomes, artifical membranous lipid vesicles, have been used in this study as model structures for biological calcification processes. Liposome (containing cholesterol and phosphatidylcholine in most cases) suspensions were prepared by sonication, after which HA seed crystals were added to the suspensions and stirred at 37°C. Aliquots of the liposome suspensions were analyzed for particle size distribution and by transmission electron microscopy and electron diffraction. The results showed that HA induced aggregation of liposomes and modifications of the microscopic shapes of the liposomes in the aggregates. These data can be explained by the electron diffraction pattern where superimposition of liposome reflection and crystal reflection exists and may suggest organic-inorganic interaction. The potential of HA crystals to induce formation of liposome aggregates may be seen as a step in atherosclerotic plaques calcification.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296291
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Bone blood flow and In vitro proliferation of bone marrow and trabecular bone osteoblast-like cells in ovariectomized rats (1992)
    Springer
    Calcified tissue international 50 (1992), S. 336-341 
    Details
    ISSN: 1432-0827
    Keywords: Rat ; Osteoblast-like culture ; Ovariectomy ; Estrogens ; Bone blood supply
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Ovariectomy in the rat induces a rapid osteopenia associated with an elevated bone turnover. One hundred and twenty-day-old rats were ovariectomized (OVX) or sham-operated (n=6–8 per group and per time period studied). 45Ca accretion rate and bone blood flow (microspheres trapping technique) in the femurs were determined at 28, 42, 84, and 119 days after ovariectomy. Both parameters were markedly increased by 84 days and subsided thereafter. At the 42nd day, when bone turnover was maximal, bone marrow and trabecular bone cultures were obtained from shamoperated and ovariectomized animals (n=10/group). Proliferation rate of bone marrow cells and trabecular osteoblast-like cells estimated by fibroblast colony-forming units (FCFU) efficiency and cell counting was markedly increased in primary and secondary cultures in ovariectomy. These data fitted well with the enhanced number of osteoblasts observed in situ in the long bone metaphyses of estrogen-depleted animals. As estrogens were shown in the literature to inhibit proliferation of the red cell line and of other hemopoietic lines, it is possible that estrogens, through a general mechanism, inhibit hemopoietic and stromal lines and also the proliferation of bone marrow-derived trabecular bone cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301631
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    The influence of tactile stimulation of nipples on the milk ejection reflex in the rat (1992)
    Springer
    Journal of comparative physiology 170 (1992), S. 645-650 
    Details
    ISSN: 1432-1351
    Keywords: Milk ejection reflex ; Positive pressure oscillations ; Motor activity of pups ; Tactile stimulation of nipples ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Changes of positive pressure exerted by pups on nipples during sucking were investigated using anesthetized, lactating dams. It was found that, every 50–60 s, individual pups performed bouts of pressure oscillations (3/s) of high amplitude which lasted about 10–12 s and coincided with periods of increased motor activity. During the intervals, when pups were quiet, series of low-amplitude oscillations (3/s) were also observed. Using a strain measuring method to record the activity of sucking pups, synchronization of activity of two or more pups was found to occur periodically every 25–30 s and, most frequently, 10–30 s before the reflex increase of milk pressure. In further experiments, artificial tactile stimulation was applied to the dam's nipples using the joint action of suction and positive pressure. Following a short-term (10–20 s) increase in frequency and amplitude of artificial nipple stimulation, 60%–80% of all reflexive peaks of milk pressure were elicited with a latency of 19 ± 5 s. This suggests that there are specific conditions under which the stimulation of nipples by pups may trigger the formation of the milk ejection reflex in the rat.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00199340
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Effects of lesion of the inferior olivary complex by 3-acetylpyridine on learning and memory in the rat (1992)
    Springer
    Journal of comparative physiology 171 (1992), S. 657-664 
    Details
    ISSN: 1432-1351
    Keywords: Inferior olivary complex ; Cerebellum ; 3-acetylpyridine ; Harmaline ; Learning ; Memory ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary DA/HAN-strained male rats (pigmented rats) were submitted to two experimental tasks consisting of spatial learning (water-escape) and a passive avoidance conditioning. Both these tasks were performed by different animals. In order to destroy the inferior olivary complex, the animals were injected with 3-acetylpyridine either 9 days prior to the initial learning session or 24 h after completion of the learning task. They were retested (retrieval test) 10 days after the initial learning was achieved. Learning and retention were compared to those noted in control rats. Administration of 3-acetylpyridine before the initial learning did not prevent the spatial learning but the scores were greatly altered and the number of trials needed to reach the fixed learning criterion was much greater than in controls. However, 10 days later the animals had memorized their initial experience. Injection of 3-acetylpyridine after the initial learning session impaired memory: the animals had completely forgotten their initial learning. It can therefore be concluded that lesion of the afferent climbing fibres to the cerebellar cortex alters learning and retention of a spatial task. Such a lesion does not interfere with learning and retention of a passive avoidance conditioning, since in this condition the experimental animals injected with 3-acetylpyridine either before or after the initial learning behave similarly to controls. The effects of the inferior olivary complex lesion are obviously different according to the task to be learnt, suggesting that these two tasks do not require the integrity of the same nervous structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194113
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Effect of a five-week swimming program on rat bone: A histomorphometric study (1992)
    Springer
    Calcified tissue international 51 (1992), S. 137-142 
    Details
    ISSN: 1432-0827
    Keywords: Swimming exercise ; Bone histomorphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary To specify the exercise-induced changes on different skeletal sites, the effect of a 5-week endurance swin training was studied in rats. Eighteen Lyon strain (Sprague-Dawley) 5-week old female rats were divided into nine sedentary and nine swimming rats. Each swim training session was increased by 15 minutes from 2–6 hours per day. A histomorphometric study was performed at the primary and secondary spongiosa of the distal femur and at the secondary spongiosa of lumbar and thoracic vertebral bodies. After training, bone loss was observed in the secondary spongiosa of lumbar vertebral bodies (24.7%) and in the primary spongiosa of distal femur (15.2%). A tendency to bone loss was also detected in the secondary spongiosa of distal femur (10.8%), whereas no change was detected in thoracic vertebral bodies. In secondary spongiosa, bone loss was accompanied with a thinning of trabeculae. Total eroded surfaces and osteoid surfaces were significantly decreased in the three studied skeletal sites, suggesting a decreased bone turnover. The decreased thickness of osteoid seams in both lumbar vertebrae and distal femur could mean that the osteoblastic activity has also been altered at the cell level, leading to thinning of trabeculae. Five-week swim training with such duration and intensity of exercise appears unable to increase bone volume in rats and, therefore, causes adverse effects. The three studied bones seemed to adapt differently to experimental conditions. The lack of ground reaction forces induced by water immersion might have contributed to the observed bone loss. “Normal” gravity would be an important cofactor in the osteogenic effects of exercise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00298502
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Biphasic dose-response curves of cortisol effects on rat diaphyseal bone biomechanics (1992)
    Springer
    Calcified tissue international 50 (1992), S. 49-54 
    Details
    ISSN: 1432-0827
    Keywords: Cortisol ; Cortical bone ; Bone biomechanics ; Rat ; Femur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Doses of 8, 16 (low), 32, 48, 64 (medium), and 150 (high) mg/kg/day of cortisol were administered to groups of 8 growing rats each during 16 days, and their femurs were then submitted to 3-point bending tests at low strain rate. Low doses had no effect. Medium doses, previously shown to improve calcium (Ca) balance and weight gain in the species, augmented diaphyseal elastic and ultimate strength, stiffness, and plastic-to-elastic deformation ratio with respect to untreated controls. This effect was achieved either by enhancing bone mass (volume, sectional moment of inertia, wall/lumen ratio) without changes in material quality parameters (32 mg/kg/day) or, conversely, by increasing bone tissue mechanical properties (stress, modulus of elasticity) not affecting bone geometry (48 and 64 mg/kg/day). The highest dose, known to depress Ca balance and weight gain, impaired diaphyseal mechanical performance in controls by substantially reducing bone mass without major variation in bone material properties, that is, developing a true osteopenic state in mechanical terms. The energy elastically absorbed per unit volume (proportional to the risk of comminute fractures) was greater with the highest dose because of enhanced deformability and diminished bone mass. The biphasic dose-response curves obtained, grossly parallel to those previously demonstrated for metabolic actions of cortisol in the same species, showed that biomechanical repercussion of this treatment on bone depends on different, dose-dependent effects which vary independently in temporal course, intensity, and sign.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297297
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    The extracellular matrix of cartilage in the growth plate before and during calcification: Changes in composition and degradation of type II collagen (1992)
    Springer
    Calcified tissue international 50 (1992), S. 327-335 
    Details
    ISSN: 1432-0827
    Keywords: Growth plate ; Collage ; Proteoglycans ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Calcification occurs in the extracellular matrix of the hypertrophic zone of the growth plate when the extra-cellular matrix volume is reduced to a minimum and alkaline phosphatase content is maximal. The present study shows that significant quantitative and qualitative changes occur in the composition and structure of macromolecules in the extracellular matrix before and during calcification in the proximal tibial growth plate of the bovine fetus. These were detected in part by using microchemical and microimmuno-chemical analyses of sequential transverse frozen sections at chemical analyses of sequential transverse frozen sections at defined sites throughout the growth plate. Concentrations of matrix molecules in the extracellular matrix have not previously been determined biochemically. They were measured per unit matrix volume by using combined immunochemical/chemical-histomorphometric analyses. The concentrations within the extracellular matrix of the C-propeptide of type II collagen, aggregating proteoglycan (aggrecan), and hyaluronic acid all progressively increased in the maturing and hypertrophic zones, being maximal (or near maximal) at the time of initiation of mineralization. These results for proteoglycan are contrary to some earlier reports of a loss of proteoglycan prior to mineralization which measured the tissue content of proteoglycan rather than that present in the extracellular matrix, the volume of which is progressively reduced as the growth plate matures. The C-propeptide data provides a quantitative confirmation of previous immunohistochemical studies. Total collagen concentration (measured as hydroxyproline) in the extracellular matrix initially increased through the proliferating and maturing zones but then rapidly decreased in the hypertrophic zone. Immunohistochemical studies revealed that this is associated with the unwinding of the triple helix of type II collagen (previously shown to result from cleavage) which starts in pericellular sites in the zone of maturation (when type X collagen is first synthesized) and then extends throughout the hypertrophic zone. The significance of these matrix changes in the development and mineralization of the growth plate is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301630
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Calcium ion activity and pH in the odontoblast-predentin region: Ion-selective microelectrode measurements (1992)
    Springer
    Calcified tissue international 50 (1992), S. 134-136 
    Details
    ISSN: 1432-0827
    Keywords: Calcification ; Dentinogenesis ; Odontoblast ; Calcium transport ; Ion-selective microelectrode ; pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Ca2+ ion activities and pH were measured in the odontoblast/predentin region of rat incisors by means of the microelectrode technique. In Ringer solution, the apparent resting membrane potential of odontoblasts was determined to be -24±4 mV (mean±SE), whereas the odontoblast intracellular pH was found to be 6.66±0.02. The values obtained are within the range of other cell types, as measured in similar incubating solutions. The pH in the extracellular predentin was higher than the intracellular pH, 7.00±0.02. The Ca2+ ion activity in predentin (pCa=2.94±0.15) was found to be significantly (P〈0.001) higher than that in the dental pulp extracellular fluid (pCa=3.37±0.14). The 2–3 times higher calcium activity extracellularly in predentin, compared with the dental pulp, implies the existence of some ion-concentrating mechanism across the odontoblast layer in the direction of the mineralization front.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00298790
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Different forms of alkaline phosphatase in adult rat femur. Effect of a Vitamin D3-deficient diet and of a sorbitol-enriched diet (1992)
    Springer
    Calcified tissue international 50 (1992), S. 433-438 
    Details
    ISSN: 1432-0827
    Keywords: Bone alkaline phosphatase ; Rat ; Vitamin D ; Sorbitol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In the femoral extremities of the adult rat containing the metaphysis, the epiphyseal cartilage, and the epiphysis, four alkaline phosphatase (AP) forms were distinguished on polyacrylamide gel electrophoresis. Two soluble forms were present in the 160,000 g supernatant: one of Mr 165 kDa and another of Mr 110–115 kDa, which exhibited a strong catalytical activity. Moreover, from the pellet, three membrane-bound forms of Mr 130, 110–115, and 100 kDa could be extacted with sodium deoxycholate. When denaturated AP was visualized by postelectrophoretic autoradiography of the phosphorylated intermediates, subunits always appeared as three monomers of Mr 75–80, 60–70, and 50–60 kDa. As four native forms but only three types of subunits were found to be present in the femur, it seems that, apart from homodimers, some heterodimers could also occur. Three types of diets were administered to three groups of rats for 5 weeks. Two are known to disturb bone mineralization: (1) a vitamin D3-deficient diet, and (2) the same as (1) but enriched with 12% sorbitol. The third was a normal diet containing vitamin D3. Concerning the effects on AP of dietary sorbitol and the vitamin D3-deficient diet, it was found that rats receiving the diet supplemented with sorbitol showed a substantial rise in the activity of the Mr 165 kDa form with the concomitant appearance of a new monomer of Mr 100 kDa. In contrast, rats fed the vitamin D3-deficient diet always displayed an increase in enzyme activity, principally of the Mr 100 and 110 kDa forms. In conclusion, the femur extracts of normal rats contained different forms of AP: either soluble 110–115 and 165 kDa forms or membrane-bound 130, 110–115, and 100 kDa forms. The administration of sorbitol-enriched diet induced a marked increase of the 165 kDa form whereas the administration of vitamin D3-deficient diet increased the 100 and 110 kDa forms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296774
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Time-dependent changes of collagen cross-links and their precursors in the culture of osteogenic cells (1992)
    Springer
    Calcified tissue international 50 (1992), S. 473-480 
    Details
    ISSN: 1432-0827
    Keywords: Osteoblasts ; Collagen ; Cross-links ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The early stage of cross-link formation in bone collagen was studied in a cell culture system. An osteogenic cell line that produces and accumulates a remarkably high amount of collagen, and that eventually forms bone-like structures, was used in this study for its time-dependent development of reducible cross-links. It was found that precursors of the cross-link, dehydro-dihydroxynorleucine and dehydro-hydroxynorleucine became detectable as soon as the cells attained a confluent state. They showed maximal amounts at day 3–5 after confluence, but substantially disappeared at day 10 after confluence. In contrast, two characteristic cross-links of bone collagen, dehydrodihydroxylysinonorleucine dehydro-DHLNL and dehydrohydroxylysinonorleucine (dehydro-HLNL), which were present in trace amounts at the stage of cell confluence, gradually increased in amount and reached a plateau at day 10, just when their precursors disappeared. Thus, it was found that there was a time lag of about a week between the maximal formations of precursors and cross-links of bone collagen in this system. The significance of this time lag was interpreted in terms of the minimum essential accumulation of collagen for the precursor-product transition. The ratio of dehydro-DHLNL to dehydro-HLNL was as low as 0.7 at day 3 after confluency, increased to 4.2 at day 20, the period just before mineralization began, and decreased thereafter, suggesting a qualitative change in bone collagen associated with mineralization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296780
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Synthetic parathyroid hormone-like protein (1–74) is anabolic for bone in vivo (1992)
    Springer
    Calcified tissue international 51 (1992), S. 30-34 
    Details
    ISSN: 1432-0827
    Keywords: PTHRP ; Anabolic ; Rat ; Bone ; Potency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Parathyroid hormone-related protein (PTHRP) has recently been purified from human tumors associated with the syndrome of humoral hypercalcemia of malignancy. The gene encoding PTHRP has been cloned, and based on predicted amino acid sequence, polypeptides comprising the first 36 [36Tyr(1–36) PTHRP amide] and 74 [(1–74)PTHRP] amino acids have been synthesized. Human (h) PTHRP (1–36) and (1–74) are potent bone-resorbing agents, and are catabolic for bone in vivo when given continuously at high doses. Bovine parathyroid hormone (bPTH) (1–34) is also catabolic for bone at high dose levels, but when given in low doses for weeks to months, it is anabolic. Although PTHRP possess several PTH-like properties in bone, hPTHRP (1–34) is reported to be only weakly anabolic in vivo. As polypeptide length influences PTHRP action, we evaluated hPTHRP(1–74) as an anabolic agent for bone in vivo. Twenty-four 4-week-old male Sprague-Dawley rats were given daily subcutaneous injections of hPTHRP(1–74) (1 and 2 nmol/100 g body weight, bw), bPTH(1–34) (4 nmol/100 g bw) or vehicle. Rats were sacrificed on day 12, and serum calcium, phosphorus, and 1,25 dihydroxyvitamin D and femoral bone dry weight, calcium content, and hydroxyproline content were measured. Serum calcium and phosphorus were equivalent in all groups. A significant increase in dry bone weight was observed in both PTHRP-treated groups compared with controls. PTHRP also caused a significant, dose-dependent increase in bone calcium and hydroxypro-line content. Results of these studies indicate that PTHRP (1–74) is anabolic for bone in vivo when administered at low-dosage levels for a prolonged period.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296214
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Receptor-mediated and adsorptive endocytosis by male germ cells of different mammalian species (1992)
    Springer
    Cell & tissue research 268 (1992), S. 471-478 
    Details
    ISSN: 1432-0878
    Keywords: Testis ; Endocytosis ; Spermatogenesis ; Spermatogonia ; Spermatocytes ; Spermatids ; Transferrin ; Ferritin ; Sertoli cells ; Mouse ; Rat ; Monkey, Macaca fascicularis (Primates)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The routes for adsorptive and receptor-mediated endocytosis were studied in vivo after microinjection of tracers into the lumen of the seminiferous tubules, and in vitro in isolated germ cells of different mammals. Cationic ferritin was located on the plasma membrane, in vesicles, in tubules, in multivesicular bodies and in lysosome-like granules of mouse spermatocytes. In these cells the number of multivesicular bodies varied during spermatogenesis. Spermatids and to a lesser extent residual bodies also performed adsorptive endocytosis. In the rat and monkey (Macaca fascicularis) diferric transferrin was specifically taken up by germ cells via receptor-mediated endocytosis. The labelling was observed subsequently in membrane pits, vesicles, endosome-like bodies and pale multivesicular bodies. A progressive decrease in the frequency of the labelling of the germ cells by transferrin-gold particles was observed from spermatogonia to spermatocytes and to early spermatids, which could indicate that iron is particularly required by germ cells during the mitotic and meiotic processes. Adsorptive and receptor-mediated endocytosis therefore occurs in all classes of germ cells. These endocytic processes are most probably required for germ cell division, differentiation and metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319154
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Specialized calciferous cells in the marine algaRhodogorgon carriebowensis and their implications for models of red algal calcification (1992)
    Springer
    Protoplasma 166 (1992), S. 89-98 
    Details
    ISSN: 1615-6102
    Keywords: Calcification ; Calcium carbonate ; Rhodogorgon ; Red algae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Calcification inRhodogorgon carriebowensis J. Norris et Bucher was associated with a particular cell type in the cortex. Calciferous cells were 4–6 times the length of cortical assimilatory cells. The distal two-thirds of the calcifying cell was invested with a thick wall that stained with periodic acid Schiff. Thick fibrils formed a reticulum and surrounded grains of calcium carbonate that ranged in shape from rhombohedral to subspherical and were up to 200 nm in greatest dimension. The proximal third of the cell was a tapering uncalcified stalk. The narrow base of the cell was attached to the subtending cell of the fascicle by a normal septum with a pit plug. The cell within the calcified wall matrix was usually flattened and had a very small volume. Cellular contents were dense; even when organelles could be discerned, they could not be identified. X-ray microanalysis revealed that other elements commonly found mixed with calcium carbonate are virtually absent from mineral deposits inR. carriebowensis, but electron diffraction study showed d-spacings that varied from those of pure calcite. Current models of red algal calcification are discussed in light of the findings on this alga.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01320147
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    An analysis of codon usage in mammals: Selection or mutation bias? (1991)
    Springer
    Journal of molecular evolution 33 (1991), S. 442-449 
    Details
    ISSN: 1432-1432
    Keywords: Humans ; Mouse ; Rat ; Codon usage ; Mutation bias ; Selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A new statistical test has been developed to detect selection on silent sites. This test compares the codon usage within a gene and thus does not require knowledge of which genes are under the greatest selection, that there exist common trends in codon usage across genes, or that genes have the same mutation pattern. It also controls for mutational biases that might be introduced by the adjacent bases. The test was applied to 62 mammalian sequences, the significant codon usage biases were detected in all three species examined (humans, rats, and mice). However, these biases appear not to be the consequence of selection, but of the first base pair in the codon influencing the mutation pattern at the third position.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02103136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    Chemical coding of endocrine cells of the airways: presence of helodermin-like peptides (1991)
    Springer
    Cell & tissue research 265 (1991), S. 425-433 
    Details
    ISSN: 1432-0878
    Keywords: Regulatory peptides ; Serotonin ; Protein gene product 9.5 (PGP) ; Respiratory tract ; Neuroendocrine cells ; Mouse ; Rat ; Harnster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The epithelium of the airways is rich in endocrine cells containing serotonin and/or a wide variety of regulatory peptides. These cells usually occur in clusters in the lungs but are also found scattered in the larynx and trachea. In the present study, endocrine cells in the airways of mouse, rat, hamster, guinea pig, pig, sheep and squirrel monkey were examined for the presence of serotonin, helodermin-like peptides and other regulatory peptides using immunocytochemistry and radioimmunoassay. In addition, we looked for the protein gene product 9.5 (PGP), which occurs in many peptide hormone-producing endocrine cells in the body. Both clustered and scattered endocrine cells in the airways were found to display coexistence of serotonin and peptides, such as a helodermin-like peptide, calcitonin and calcitonin gene-related peptide (CGRP). The PGP-immunoreactive cells were numerous and included elements containing serotonin and/or regulatory peptides. An additional PGP-immunoreactive endocrine cell population lacked serotonin and regulatory peptides. Helodermin-immunoreactive material was demonstrated in endocrine cells of the airways in the mouse and hamster but not in any of the other species studied. Serotonin was an endocrine cell constituent in all the species studied. Calcitonin and CGRP could be demonstrated by immunocytochemistry in the mouse, rat, and hamster, but not in the guinea pig, sheep, pig and monkey. In the hamster airways double immunostaining indicated that the helodermin-like peptide occurred in a subpopulation of the CGRP- and serotonin-containing cells. Most of the CGRP-containing cells stored serotonin; some of them also contained calcitonin. The chemical coding of these cells resembled that of the thyroid C cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340865
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Atrial and brain natriuretic peptides share binding sites on cultured cells from the rat trachea (1991)
    Springer
    Cell & tissue research 265 (1991), S. 555-565 
    Details
    ISSN: 1432-0878
    Keywords: Atrial natriuretic peptide ; Brain natriuretic peptide ; Binding sites ; Trachea ; Autoradiography ; Cell culture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary We examined the distribution of binding sites for alpha-atrial natriuretic peptide (125I-ANP1–28) and the recently discovered porcine brain natriuretic peptide (125I-pBNP) on immunocytochemically identified cells in dissociated culture preparations of the rat trachea. Specific binding sites for both 125I-ANP1–28 and 125I-pBNP were evenly distributed over distinet subpopulations of smooth muscle myosin-like immunoreactive muscle cells, fibronectin-like immunoreactive fibroblasts and S-100-like immunoreactive glial cells. Neither keratin-like immunoreactive epithelial cells nor protein gene product 9.5-like immunoreactive paratracheal neurones expressed natriuretic peptide binding sites, although autoradiographically labelled glial cells were seen in close association with both neuronal cell bodies and neurites. The binding of each radiolabelled peptide was abolished by the inclusion of either excess (1 μM) unlabelled rat ANP or excess unlabelled porcine BNP, suggesting that ANP and BNP share binding sites in the trachea. Furthermore, the ring-deleted analogue, Des-[Gln18, Ser19, Gly20, Leu21, Gly22]-ANF4–23-NH2, strongly competed for specific 125I-ANP1–28 and 125I-pBNP binding sites in the tracheal cultures; this suggests that virtually all binding sites were of the “clearance” (ANP-C or ANF-R2) receptor subtype.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00340880
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Patterns of mineralization in vitro (1991)
    Springer
    Cell & tissue research 263 (1991), S. 483-493 
    Details
    ISSN: 1432-0878
    Keywords: Mineralization in vitro ; Organoid culture ; Calvarial cells ; Matrix vesicles ; Cell necrosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Various patterns of mineralization are found in the organism during fetal and postnatal development. Different findings and theories have been published in the literature with regard to the mechanisms of mineralization, many of which are controversely discussed. In the present study the different patterns of mineralization observed in the organoid culture system of fetal rat calvarial cells were investigated by electron microscopy. In organoid culture, calvarial cells grow and differentiate at high density, and deposition of osteoid and mineralization of the matrix occur to a very high extent. Different types of mineralization could be observed more or less simultaneously. It was found that hydroxyapatite crystals were formed at collagen fibrils as well as in the interfibrillar space. Mineralization was frequently seen in necrotic cells and cellular remnants as well as in extra-and intracellular vesicles. Addition of bone or dentin matrices or the artificial hydroxyapatite Interpore 200 to the cells caused an increased mineralization in the vicinity and on the surface of the matrices with and without participation of collagen. On previously formed mineralized nodules, an apposition of mineralizing material appeared due to matrix secretion by osteoblasts. It is concluded that initiation of mineralization occurs-at least in vitro-at every nucleation point under appropriate conditions. These mineralization foci enlarge by further apposition as well as by cellular secretion of a mineralizing matrix. Furthermore, cell necroses may liberate mineralizable vesicles. All these patterns of mineralization are the result of different activities of one cell type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327281
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Patterns of co-existence of peptides and differences of nerve fibre types associated with noradrenergic and non-noradrenergic (putative cholinergic) neurons in the major pelvic ganglion of the male rat (1991)
    Springer
    Cell & tissue research 266 (1991), S. 405-415 
    Details
    ISSN: 1432-0878
    Keywords: Pelvic plexus ; Autonomic ganglia ; Neuropeptides ; Tyrosine hydroxylase ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pelvic ganglia supply cholinergic and noradrenergic nerve pathways to many organs. Other possible transmitters are also present in these nerves, including peptides. Multiple labelling immunofluorescence techniques were used in this study of the male rat major pelvic ganglion (MPG) to examine: (1) the peptides present in noradrenergic (tyrosine hydroxylase (TH)-positive) and non-noradrenergic (putative cholinergic) neurons, and (2) the types of peptide-containing nerve fibres closely associated with these two groups of neurons. The distribution of the peptide galanin (GAL) within the MPG was also investigated. All of the TH-neurons contained neuropeptide Y (NPY), but none of the other tested peptides. However, many NPY neurons did not contain TH and may have been cholinergic. TH-negative neurons also displayed vasoactive intestinal peptide (VIP), enkephalin (ENK) or GAL. VIP and NPY formed the most common types of putative cholinergic pelvic neurons, but few cells contained both peptides. Many ENK neurons exhibited VIP, NPY or GAL. Varicose nerve terminals surrounding ganglion cells contained ENK, GAL, somatostatin (SOM) and cholecystokinin (CCK). These peptide-immunoreactive fibres were more often associated with the non-noradrenergic (putative cholinergic) than the noradrenergic neurons; two types (SOM and CCK) were preferentially associated with the non-noradrenergic NPY neurons. GAL was distributed throughout the MPG, in small neurons, scattered small, intensely fluorescent (SIF) cells, and both varicose and non-varicose nerve fibres. The nerve fibres were concentrated near the pelvic and penile nerves; most of the varicose fibres formed “baskets” surrounding individual GAL-negative somata.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318197
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Co-occurrence of immunoreactive calcitonin and calcitonin gene-related peptide in neuroendocrine cells of rat lungs (1991)
    Springer
    Cell & tissue research 264 (1991), S. 555-561 
    Details
    ISSN: 1432-0878
    Keywords: Neuropeptides ; Colocalization ; Neuroepithelial bodies ; APUD cells ; Gene expression ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Neuroendocrine cells of the lung, occurring singly or in clusters known as neuroepithelial bodies, contain a variety of biologically active compounds, including several neuropeptides. We have investigated the localization of calcitonin and calcitonin gene-related peptide (CGRP) within single and grouped neuroendocrine cells in the respiratory epithelium of rats by an immunohistochemical double-staining technique which uses specific antisera raised in heterogeneous animal species. Calcitonin- and CGRP-immunoreactivities were nearly totally co-localized in both single neuroendocrine cells and neuroepithelial bodies. CGRP-immunoreactivity was also present in neurons in the jugular, nodose and dorsal root ganglia. The calcitonin-immunoreactivity in neuroendocrine cells, as in thyroid parafollicular (C) cells, was abolished by preincubation of the anticalcitonin serum with synthetic calcitonin. The CGRP-immunoreactivity in neuroendocrine cells and in the neuronal cells was abolished by preincubation of anti-CGRP serum with synthetic CGRP. Thus, while the calcitonin gene is expressed exclusively or predominantly as either calcitonin or CGRP in all other tissues except thyroid C-cells, our results strongly suggest that both peptides are expressed in the rat bronchopulmonary neuroendocrine cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319045
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    Met5-enkephalin-Arg6-Gly7-Leu8-immunoreactive nerve fibers in the major salivary glands of the rat: evidence for both sympathetic and parasympathetic origin (1991)
    Springer
    Cell & tissue research 264 (1991), S. 15-22 
    Details
    ISSN: 1432-0878
    Keywords: Salivary glands ; Innervation ; Immunohistochemistry ; Met5-enkephalin-Arg6-Gly7-Leu8 ; Tyrosine hydroxylase ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The localization of the proenkephalin A-derived octapeptide, Met5-enkephalin-Arg6-Gly7-Leu8 (MEAGL), was studied in the major salivary glands of Sprague-Dawley and Wistar rats with the indirect immunofluorescence method. MEAGL-immunoreactive nerve fibers were found around the acini, along intra-and interlobular salivary ducts and in close contact with blood vessels. In the parotid and submandibular glands tyrosine hydroxylase (TH) immunoreactivity was observed in nerve fibers around the acini, in association with intra- and interlobular salivary ducts and around blood vessels, while in the sublingual gland TH-immunoreactive nerve fibers were only seen around blood vessels. Parasympathetic neurons in submandibular ganglia contained MEAGL immunoreactivity. Moderate TH immunoreactivity was seen in some neurons of the submandibular ganglia. A subpopulation of sympathetic principal neurons in the superior cervical ganglion were immunoreactive for both MEAGL and TH. In the trigeminal ganglion, no MEAGL-immunoreactive sensory neurons or nerve fibers were observed. Superior cervical ganglionectomies resulted in a complete disappearance of TH-immunoreactive nerve fibers, while MEAGL-immunoreative nerve fibers were still present in the glands. The presence of MEAGL immunoreactivity in neurons of both sympathetic superior cervical ganglia and parasympathetic submandibular ganglia and the results of superior cervical ganglionectomies suggest, that MEAGL-immunoreactive nerve fibers in the major salivary glands of the rat have both sympathetic and parasympathetic origin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305718
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Effects of prolonged sodium restriction on the morphology and function of rat adrenocortical autotransplants (1991)
    Springer
    Cell & tissue research 265 (1991), S. 35-41 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal autotransplants ; Sodium restriction ; Mineralocorticoid hormones ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Regenerated adrenocortical nodules were obtained by implanting fragments of the capsular tissue of excised adrenal glands into the musculus gracilis of rats (Belloni et al. 1990). Five months after the operation, operated rats showed a normal basal blood level of corticosterone, but a very low concentration of circulating aldosterone associated with a slightly increased plasma renin activity (PRA). Regenerated nodules were well encapsulated and some septa extended into the parenchyma from the connective-tissue capsule. The majority of parenchymal cells were similar to those of the zonae fasciculata and reticularis of the normal adrenal gland, while zona glomerulosa-like cells were exclusively located around septa (juxta-septal zone; JZ). In vitro studies demonstrated that nodules were functioning as far as glucocorticoid production was concerned, while mineralocorticoid yield was very low. Prolonged sodium restriction significantly increased PRA and plasma aldosterone concentration, and provoked a marked hypertrophy of JZ, which was due to increases in both the number and average volume of JZ cells. Accordingly, the in vitro basal production of aldosterone and other 18-hydroxylated steroids was notably enhanced. The plasma level of corticosterone, as well as zona fasciculata/reticularis-like cells and in vitro production of glucocorticoids by regenerated nodules were not affected. These findings, indicating that autotransplanted adrenocortical nodules respond to a prolonged sodium restriction similar to the normal adrenal glands, suggest that the relative deficit in mineralocorticoid production is not due to an intrinsic defect of the zona glomerulosa-like JZ, but is probably caused by the impairment of its adequate stimulation under basal conditions. The hypothesis is advanced that the lack of splanchnic nerve supply and chromaffin medullary tissue in regenerated nodules may be the cause of such an impairment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318136
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Initial calcification of the upper permanent incisor in Japanese macaques (1991)
    Springer
    Primates 32 (1991), S. 265-268 
    Details
    ISSN: 0032-8332
    Keywords: Incisor crown formation ; Calcification ; Enamel ; Japanese macaques ; Macaca fuscata ; Sexual variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Fifteen laboratory-born Japanese macaques,Macaca fuscata (Blyth, 1875), were examined radiographically for the timing of initial crown calcification of the permanent upper first incisors. The mean age of initial calcification was 199.8 days in females and 204.7 days in males; the sexual difference was significant (p〈.05). Precocious incisor calcification in females inM. fuscata resembles that inM. nemestrina andHomo sapiens.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02381185
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Adaptation of intestinal hydrolases to starvation in rats: effect of thyroid function (1991)
    Springer
    Journal of comparative physiology 161 (1991), S. 357-361 
    Details
    ISSN: 1432-136X
    Keywords: Thyroidectomy ; Sucrase ; β-Galactosidases ; Aminopeptidase ; Messenger RNA ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of long-term starvation on the activities of sucrase, lactase, and aminopeptidase, and on their respective mRNA were determined in the small intestine of thyroidectomized and sham-operated adult rats. Thyroidectomy reduced the protein loss at the level of the intestinal brush border membranes during starvation. Prolonged fasting caused a significant decrease in sucrase activity, but thyroidectomy partly prevented this effect. However, the amount of the corresponding mRNA dropped during long term starvation without incidence of thyroidectomy. Lactase activity in the brush border membranes was increased by starvation, and thyroidectomy caused a further elevation of the enzyme activity. Simultaneously, lactase mRNA content rose only slightly compared to the enzyme activity. Amnopeptidase activity and mRNA content decreased during starvation and thyroidectomy did not prevent this process. These results indicate that intestinal hydrolases respond non-coordinately to long-term food deprivation. In addition, the thyroid status of the animals has a direct influence on the adaptation of several brush border hydrolases to starvation. This suggests that the drop in plasma thyroid hormones during fasting allows a better maintenance of protein content and of hydrolase activities in the brush border membranes of the small intestine. These adaptive processes seemed to be partly controlled at a post-transcriptional level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00260793
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Studies on chitin and calcification in the inner layers of the shell of Anodonta cygnea (1991)
    Springer
    Journal of comparative physiology 161 (1991), S. 413-418 
    Details
    ISSN: 1432-136X
    Keywords: Chitin ; Aragonite ; Calcification ; Crystalline shape ; Anodonta cygnea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary An orthorhombic structure α-chitin, probably in the form of a chitin-protein complex, was identified in the matrix of the shell of Anodonta cygnea by X-ray diffraction. Aragonite crystals of pseudohexagonal symmetry were also found by a Lauegram on the nacreous layer of the shell. The orthorhombic structure of these two compounds together with the identical reticular spacing d110 corroborate, in Anodonta cygnea, the indirect chitin-aragonite relationships already suggested for molluscan shells. Observations with SEM in the inner surface of the shell showed CaCO3 crystals with irregular geometrical shapes in spring and summer and regular geometrical shapes in autumn and winter. The more elaborate aspect appearing in winter corresponds to an accurate hexagonal shape. This suggests that the observed variability may depend on the balance between calcium and hydrogen ions in the extrapallial fluid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00260802
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Effect of L-carnitine and stimulated lipolysis on muscle substrates in the exercising rat (1990)
    Springer
    Cellular and molecular life sciences 46 (1990), S. 457-458 
    Details
    ISSN: 1420-9071
    Keywords: Rat ; carnitine ; lipolysis ; exercise ; glycogen ; triglycerides ; muscle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To test the effect of L-carnitine on glycogen sparing when fat oxidation is increased, 100 mg/kg/d were given to rats orally for 3 days, resulting in 1.8-fold higher muscle carnitine levels. Even when FFA were raised by heparin-stimulated lipolysis, the rate of glycogen degradation was not reduced during exercise.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01954228
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Cell allocation to the inner cell mass and the trophectoderm in rat embryos during in vivo preimplantation development (1990)
    Springer
    Development genes and evolution 198 (1990), S. 257-263 
    Details
    ISSN: 1432-041X
    Keywords: Inner cell mass ; Blastocyst ; Morula ; Implantation ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The number of trophectoderm (TE) and inner cell mass (ICM) cells was determined by complementmediated lysis and differential staining in rat embryos collected at different times during in vivo preimplantation development. At 90 h after fertilization, two groups of morulae were discriminated according to the presence or absence of detectable ICM cells, and the analysis of their total cell number indicated that acquisition of a permeability seal between TE cells begins at the 14-cell stage. On the other hand, our data confirmed that blastocoele formation occurs after the fourth cleavage division in the rat. The total cell number increased exponentially with time in blastocysts recovered between 90 h and 127 h but the cell kinetics of TE and ICM cells were different. The proportion of ICM cells consequently varied throughout blastocyst development, with a peak value for expanded blastocysts at 103 h. Finally, a linear-quadratic relationship was found between the numbers of TE and ICM cells when all the embryos with a detectable ICM were analysed together.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00377392
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Peripheral nervous control of cold-induced reduction in the respiratory quotient of the rat (1990)
    Springer
    International journal of biometeorology 34 (1990), S. 24-27 
    Details
    ISSN: 1432-1254
    Keywords: Cold-induced thermogenesis ; Peripheral nervous system ; Respiratory quotient ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract Cold-exposed rats show a reduction in the respiratory quotient which is indicative of a relative shift from carbohydrates to lipids as substrates for oxidative metabolism. In the present study, the effects of food deprivation and cold exposure on the respiratory quotient were observed. In addition, the involvement of the three main branches of the peripheral nervous system (sympathetic, parasympathetic, and somatic) was investigated by means of synaptic blockade with propranolol, atropine, and quinine, respectively. Both propranolol and quinine blocked the cold-induced decrease in respiratory quotient and increase in heat production, whereas atropine had only minor and very brief effects. It is concluded that both the sympathetic and somatic branches are involved in the metabolic changes associated with cold-induced thermogenesis and that the increase in metabolic heat production involves a shift from carbohydrate to lipid utilization irrespective of which of the two branches is activated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01045816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Neuropeptide Y: presence in sympathetic and parasympathetic innervation of the nasal mucosa (1990)
    Springer
    Cell & tissue research 259 (1990), S. 119-128 
    Details
    ISSN: 1432-0878
    Keywords: Nasal mucosa ; Neuropeptide Y (NPY) ; Vasoactive intestinal polypeptide (VIP) ; Peptide histidine isoleucine (PHI) ; Noradrenaline ; Sympathetic/parasympathetic innervation ; Pig ; Cat ; Guinea-pig ; Rat ; Man
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The occurrence of neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in the sympathetic and parasympathetic innervation of the nasal mucosa was studied in various species including man. A dense network of NPY-immunoreactive (IR) fibres was present around arteries and arterioles in the nasal mucosa of all species studied. NPY was also located in nerves around seromucous glands in pig and guinea-pig, but not in rat, cat and man. The NPY-IR glandular innervation corresponded to about 20% of the NPY content of the nasal mucosa as revealed by remaining NPY content determined by radioimmunoassay after sympathectomy. These periglandular NPY-positive fibres had a distribution similar to the VIP-IR and PHI-IR nerves but not to the noradrenergic markers tyrosine hydroxylase (TH) or dopamine-β-hydroxylase (DBH). The NPY nerves around glands and some perivascular fibres were not influenced by sympathectomy and probably originated in the sphenopalatine ganglion where NPY-IR and VIP-IR ganglion cells were present. The venous sinusoids were innervated by NPY-positive fibres in all species except the cat. Dense NPY and DBH-positive innervation was seen around thick-walled vessels in the pig nasal mucosa; the latter may represent arterio-venous shunts. Double-labelling experiments using TH and DBH, and surgical sympathectomy revealed that the majority of NPY-IR fibres around blood vessels were probably noradrenergic. The NPY-positive perivascular nerves that remained after sympathectomy in the pig nasal mucosa also contained VIP/PHI-IR. The major nasal blood vessels, i.e. sphenopalatine artery and vein, were also densely innervated by NPY-IR fibres of sympathetic origin. Perivascular VIP-IR fibres were present around small arteries, arterioles, venous sinusoids and arterio-venous shunt vessels of the nasal mucosa whereas major nasal vessels received only single VIP-positive nerves. The trigeminal ganglion of the species studied contained only single TH-IR or VIP-IR but no NPY-positive ganglion cells. It is concluded that NPY in the nasal mucosa is mainly present in perivascular nerves of sympathetic origin. In some species, such as pig, glandular and perivascular parasympathetic nerves, probably of VIP/PHI nature, also contain NPY.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571436
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    Internalized gap junctions in ciliary epithelium of rabbit and rat (1990)
    Springer
    Cell & tissue research 261 (1990), S. 205-210 
    Details
    ISSN: 1432-0878
    Keywords: Ciliary process ; Epithelial cells ; Gap junction ; Autophagy ; Rabbit ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transmission electron microscopy was used to examine internalized gap junctions (IGJ) in rabbit and rat ciliary epithelial cells. A prominent feature of all the specimens studied was the presence of different images of IGJ membrane that entrapped a portion of an adjoining cell. We documented and analyzed more than 500 gap junction (GJ) vacuoles and invaginations, the latter comprising less than 20% of all the structures examined. With ten exceptions found in non-pigmented cells, all the IGJ were unidirectionally internalized within the cytoplasm of pigmented epithelial cells. Morphological signs of autophagic degradation of GJ vacuoles were observed. An essential finding was that once a GJ membrane started to invaginate, a “lucidation” of a part of the protruding cytoplasm occurred; no planar GJ membranes exhibited such an alteration. The present findings suggest that IGJ derived from the epithelium of ciliary processes arise through an invagination-endocytosis mechanism and are degraded autophagically. This phenomenon may be relevant to aqueous humor production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00329453
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Autoradiographic localization of specific atrial natriuretic peptide binding sites on immunocytochemically identified cells in cultures from rat and guinea-pig hearts (1990)
    Springer
    Cell & tissue research 261 (1990), S. 301-312 
    Details
    ISSN: 1432-0878
    Keywords: Atrial natriuretic peptide ; Binding sites ; Heart ; Autoradiography ; Cell culture ; Rat ; Guineapig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Dissociated cell culture preparations from rat and guinea-pig atria and interatrial septum, and from rat ventricles were studied using a combined autoradiographic and immunocytochemical approach. Alphaatrial natriuretic peptide (125I-ANP1-128) binding sites were confined to subpopulations of identified non-neuronal cells in each type of culture preparation, and had distinct patterns of labelling. The density of ANP1-28 binding sites was substantially greater in guinea-pig cultures than in rat cultures and was least in rat ventricular cultures. ANP1-28-labelled subpopulations of S-100-like immunoreactive glial cells were only seen in guinea-pig cultures. Von Willebrand factor (vWF)-like immunoreactive endothelial cells and vWF-negative endothelioid cells expressed ANP1-28 binding sites in both the guinea-pig and rat atrial cultures, but were unlabelled in rat ventricular cultures. In contrast, labelled subpopulations of fibronectin-like immunoreactive fibroblasts were present in all of the three types of culture preparation studied. ANP-like immunoreactive myocytes were present in both atrial and ventricular cultures. These cells did not, however, express ANP1-28 binding sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318671
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    Visualisation of specific binding sites for atrial natriuretic peptide on non-neuronal cells of cultured rat sympathetic ganglia (1990)
    Springer
    Cell & tissue research 259 (1990), S. 129-137 
    Details
    ISSN: 1432-0878
    Keywords: Atrial natriuretic peptide receptors ; Sympathetic ganglia ; Autoradiography ; Cell culture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of atrial natriuretic peptide binding sites on cells in dissociated culture preparations of neonatal rat superior cervical ganglia and in explant cultures of rat thoracic sympathetic chain ganglia has been studied. The autoradiographic visualisation of atrial natriuretic peptide binding sites has been combined with the use of specific immunocytochemical markers for glial cells (antiserum to S-100 protein), fibroblasts (antiserum to fibronectin) and neurones (antiserum to protein gene product 9.5) in order to achieve unambiguous identification of the cell types in culture. Specific binding sites for rat125I-atrial natriuretic peptide(1–28) were observed over subpopulations of fibronectin-like-immunoreactive fibroblasts and S-100-like-immunoreactive glia in the dissociated superior cervical ganglion cultures. However, only a subpopulation of fibronectin-like-immunoreactive fibroblasts possessed atrial natriuretic peptide binding sites in the explant culture preparations. No atrial natriuretic peptide-like-immunoreactive cells were present in either culture. The distribution of autoradiographic grains over individual cell surfaces in culture was uniform, but there were distinct differences in the density of labelling of single cells of the same type. This apparent variation in the number of binding sites on glial cells and fibroblasts in culture did not seem to be related to the morphology of the cells or the surrounding cell types. No sympathetic neurones were labelled with autoradiographic grains in either the dissociated or explant culture preparations. However, the presence of atrial natriuretic peptide binding sites on non-neuronal cells of sympathetic ganglia in culture may be linked to the relationship between atrial natriuretic peptide and the sympathetic nervous system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571437
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Structure of the cumulus oophorus at the time of fertilization (1990)
    Springer
    Cell & tissue research 261 (1990), S. 249-259 
    Details
    ISSN: 1432-0878
    Keywords: Cumulus oophorus ; Mucus ; Fertilization ; Rat ; Syrian hamster
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ultrastructural and morphometric techniques were employed to examine the ovulated cumulus oophorus of hamsters and rats. Observations on cumuli prepared in a variety of ways including different chemical fixation techniques and cryofixation freeze substitution were compared. It was concluded that the cumulus mucus is not arranged in lamellae or granules as has previously been suggested but is composed of molecules which form very fine filaments when properly fixed. Morphometric analysis of cumuli fixed either in situ or after being explanted into medium revealed that the distance between neighboring cumulus cells was greater with increasing distance from the oocyte. Morphometry revealed that, when placed into medium, the cumulus expands possibly due to hydration. Thus physiological experiments carried out on cumuli should be performed very shortly after cumuli are isolated. From their ultrastructure cumulus cells appear to be actively involved in protein synthesis and secretion as well as steroid production.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318666
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Ultrastructural distribution of somatostatin-14 and-28 in rat adrenal cells (1990)
    Springer
    Cell & tissue research 261 (1990), S. 517-524 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Adrenal medulla ; Somatostatin immunoreactivity ; Immunocytochemistry ; Hybridization, in situ ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Previous studies have shown that somatostatin modulates angiotensin-induced aldosterone secretion by adrenal glomerulosa cells. This effect is mediated through specific receptors which do not show any preference for somatostatin-14 (S14) or the N-extended form somatostatin-28 (S28). The study of the distribution of 125I-Tyr [Tyr0, DTrp8] S14-and 125I-Tyr[Leu8, DTrp22, Tyr25] S28-binding in frozen sections of the rat adrenal by autoradiography indicated that both peptides bind to similar loci. High concentrations of binding sites were observed in the zona glomerulosa, and low concentrations were detected in the medulla. At the ultrastructural level, immunocytochemistry after cryoultramicrotomy revealed endogenous S14-and S28-like immunoreactive material in zona glomerulosa and in medulla. In glomerulosa cells, immunoreactive material was localized at the plasma membrane level, in the cytoplasmic matrix, in the mitochondria, and in the nucleus. S14-and S28-like materials were detected in both epinephrine and norepinephrine-storing cells of the adrenal medulla. In these cells, the distribution of either immunoreactive product was similar; it was observed in cytoplasmic matrix, secretory granules and nucleus, but not at the plasma membrane level. In situ hybridization does not reveal somatostatin mRNA in zona glomerulosa or medulla. These results demonstrate that S14 and S28 bind to, and are taken up by zona glomerulosa and adrenal medullary cells, but are not produced by these cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00313531
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Cryo-electron microscopy of vitrified nerve myelin (1990)
    Springer
    Cell & tissue research 262 (1990), S. 59-66 
    Details
    ISSN: 1432-0878
    Keywords: Myelin sheath ; Rapid cryofixation ; Deepetching ; Cryoultramicrotomy ; Cryotransfer ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The ultrastructure of rat optic and trigeminal nerve myelin was studied using different cryotechniques. Replicas of rapid cryofixed and deep-etched material were compared with cryosections of chemically unfixed specimens and also of glutaraldehyde-fixed specimens. Hydrated cryosections were analysed in a cryotransfer device. The data reported here show discrepancies with the current descriptions of myelin structure based on osmium-fixed and resin-embedded material. The structures called the major line (as a fusion of the cytoplasmic surfaces of the glial cells) in conventional electron microscopy and the intraperiod line (as a fusion of the outer surfaces) are seen in the present material to represent actually aqueous spaces. The extracellular space (Espace) is most sensitive to chemical fixation and other preparation procedures, and probably also expands under pathological conditions. The virtual C-space (cytoplasmic space=major line) is more stable. The cytoplasmic surfaces are most probably joined by globular proteins (myelin basic protein). The most compact organization of myelin is seen in fresh, unfixed nerves. A continuous bilayer could not be observed and the bilayer membrane showed particulate subunits.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327746
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    Urinary bladder of rat: fine structure of normal and hypertrophic musculature (1990)
    Springer
    Cell & tissue research 262 (1990), S. 67-79 
    Details
    ISSN: 1432-0878
    Keywords: Urinary bladder ; Smooth muscle ; Hypertrophy ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the muscle of the urinary bladder in female rats is similar to that of other visceral muscles, although it is arranged in bundles of variable length, cross-section and orientation, forming a meshwork. When distended, the musculature is 100–120 μm thick, with some variation and occasional discontinuity. Extended areas of cell-to-cell apposition with uniform intercellular space occur between muscle cells, whereas attachment plaques for mechanical coupling are less common than in other visceral muscles. There are no gap junctions between muscle cells. Many bundles of microfilaments and small elastic fibres run between the muscle cells. After chronic partial obstruction of the urethra, the bladder enlarges and is about 15 times heavier, but has the same shape as in controls; the growth is mainly accounted for by muscle hypertrophy. The outer surface of the hypertrophic bladder is increased 6-fold over the controls; the muscle is increased 3-fold in thickness, and is more compact. Mitoses are not found, but there is a massive increase in muscle cell size. There is a modest decrease in percentage volume of mitochondria, an increase in sarcoplasmic reticulum, and no appreciable change in the pattern of myofilaments. Gap junctions between hypertrophic muscle cells are virtually absent. Intramuscular nerve fibres and vesicle-containing varicosities appear as common in the hypertrophic muscle as in controls. There is no infiltration of the muscle by connective tissue and no significant occurrence of muscle cell death.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327747
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    Corticotropin releasing factor increases the adrenocortical responsiveness to adrenocorticotropin (1984)
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1004-1006 
    Details
    ISSN: 1420-9071
    Keywords: Rat ; adrenocortical responsiveness ; ACTH ; plasma ; corticosterone ; plasma ; corticotropin releasing factor (CRF)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the course of studying the plasma adrenocorticotropic hormone (ACTH) and corticosterone responses to synthetic corticotropin releasing factor (CRF), we noted some disparity in the responses. A higher dose (20 μg compared with 5 μg per rat i.a.) produced an equal plasma ACTH but greater plasma corticosterone response in adult male rats. Thus, we examined the possibility that CRF increases adrenocortical responsiveness to ACTH. CRF significantly (p〈0.0005) increased the plasma corticosterone response to ACTH in rats pretreated with dexamethasone. Thus, synthetic CRF increases corticosterone secretion in rats not only by stimulating ACTH secretion, but also by increasing the adrenocortical responsiveness to ACTH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01946481
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Do prostaglandins mediate the somatostatin preventive effect on gastric lesion? (1984)
    Springer
    Cellular and molecular life sciences 40 (1984), S. 974-975 
    Details
    ISSN: 1420-9071
    Keywords: Rat ; prostaglandins ; gastric lesion ; intragastric distension model ; stress model ; indomethacin ; somatostatin preventive effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The inhibition of endogenous prostaglandin synthesis by indomethacin treatment blocks the somatostatin preventive effect on the gastric lesions induced in a stress model and has no preventive effect on an intragastric distension model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01946466
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Intracerebroventricular injection of cerebrospinal fluid (CSF) from a patient with congenital indifference to pain induces analgesia in rats (1984)
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1365-1366 
    Details
    ISSN: 1420-9071
    Keywords: Rat ; cerebrospinal fluid, human ; analgesia ; naloxone ; pain indifference, congenital ; opiates, endogenous
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary CSF from a patient with congential indifference to pain was found to produce analgesia in the rat following intracerebroventricular injections. The analgesic effect was attenuated by pretreatment with naloxone suggesting the involvement of hyperactive endogenous opiate mechanisms in this patient.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01951891
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    15-Hydroxyprostaglandin dehydrogenase and hexokinase in spontaneously hypertensive rat kidney (1984)
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1368-1369 
    Details
    ISSN: 1420-9071
    Keywords: Rat ; kidney ; hypertensive ; prostaglandin dehydrogenase ; hexokinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 15-Hydroxyprostaglandin dehydrogenase (PGDH) surged in hypertensive (SHR) and normotensive (WKY) rat kidney at 8 days of age, is greatest in SHR. Hexokinase fell in SHR at 17 days of age, but thereafter was similar to WKY. This suggests multisystem enzymatic abnormalities in SHR kidney during development of hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01951893
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Ethanol preference in rats with a prior history of acetaldehyde self-administration (1984)
    Springer
    Cellular and molecular life sciences 40 (1984), S. 1008-1010 
    Details
    ISSN: 1420-9071
    Keywords: Rat ; ethanol preference ; acetaldehyde self-administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Peripherally self-injected acetaldehyde in interaction with environmental and nutritional variables significantly enhances alcohol drinking in rats and suggests an involvement of acetaldehyde in voluntary alcohol intake.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01946483
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Co-isolation of proteolipids and calcium-phospholipid-phosphate complexes (1984)
    Springer
    Calcified tissue international 36 (1984), S. 214-218 
    Details
    ISSN: 1432-0827
    Keywords: Proteolipid ; Calcium-phospholipid-phosphate complexes ; Calcification ; Hydroxyapatite ; Membranes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary This study demonstrates that calciumphospholipid-phosphate complexes (CPLX) and calcifiable proteolipid are associatedin vivo by establishing that they can be co-isolated from calcified bacteria. Both of these membrane constituents, which support apatite formationin vitro, have been isolated independently fromBacterionema matruchotii. However, isolation of proteolipid was preceded by demineralization in 2N formic acid, thereby dissociating bound Ca, whereas isolation of CPLX included sonication of calcified bacteria in 2:1:1.5 chloroform:methanol:Tris buffer, thereby dissociating any protein. Co-isolation is possible by demineralizing the calcified bacteria with 50 mM phthalic acid, pH 5.5, followed by extraction with 2:1 chloroform:methanol, and precipitation of crude phospholipid with acetone. CPLX and proteolipid are present in all Sephadex LH-20 chromatographic fractions of the crude phospholipid and of diethyl ether precipitates of the crude phospholipid. CPLXs contain protein:phospholipid:Ca:Pi but differ in relative composition from each other and from independently isolated CPLX. The Ca:phospholipid:Pi molar ratio of diethyl ether precipitable proteolipid-CPLX is most similar to previously published values for CPLX. The protein content of CPLX accounts for all of the proteolipid apoprotein in each Sephadex LH-20 fraction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405320
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Systematic purification of free and matrix-bound phosphophoryns of bovine dentin: Presence of matrix-bound phosphophoryn as a distinct molecular entity (1984)
    Springer
    Calcified tissue international 36 (1984), S. 239-242 
    Details
    ISSN: 1432-0827
    Keywords: Phosphoprotein ; Dentin ; Calcification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Free and matrix-bound phosphophoryns, both highly phosphorylated proteins in dentin, were prepared from EDTA extract and CNBr-digests of bovine dentin. The two components were purified by DEAE-cellulose, SP-Sephadex, and gel filtration chromatography. The matrix-bound component was eluted as a distinct peak from the free component in the above chromatographic systems. Amino acid composition of the purified matrixbound component indicated that this component consisted of phosphophoryn and collagen in the ratio of 2:3 based on the number of the residues. The matrix-bound component could not be reconstituted by mixing phosphophoryn with collagen CNBr peptides. Artificial crosslink products of free phosphophoryn and collagen CNBr-peptides by the carbodiimide method showed similar properties to the physiological matrix-bound phosphophoryn. The bond between phosphophoryn and collagen of the matrix-bound component is assumed to be a covalent crosslink.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405323
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Proteolipid-lipid relationships in normal and vitamin D-deficient chick cartilage (1984)
    Springer
    Calcified tissue international 36 (1984), S. 332-337 
    Details
    ISSN: 1432-0827
    Keywords: Proteolipid ; Phospholipids ; Vitamin D ; Calcification ; Cartilage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Previous studies have shown thatin vitro calcification of chick epiphyseal cartilage matrix vesicles is proteolipid-dependent. The purpose of this research is to examine the role of proteolipid in cartilage calcificationin vivo by comparing the proteolipid concentration of normal and vitamin D-deficient chick epiphyseal cartilage, the relationship of proteolipid to other tissue lipids, and its ability to supportin vitro apatite formation. Proteolipid was isolated from the upper growth centers (reserve cell zone, upper proliferative zone) and lower growth centers (lower proliferative, hypertrophic, and calcified cartilage zones) of long-bone epiphyses from 3-week-old normal and rachitic male white leghorn chicks by Sephadex LH-20 chromatography of the crude phospholipid component of the total lipid extract. In both normal and rachitic tissue the proteolipid/dry weight and proteolipid/total lipid ratios were greater in the lower growth center than in the upper zones. No statistically significant change in the proteolipid/total lipid ratio in rachitic tissues relative to comparable cell zones in normal cartilages was observed. However, there was an increase in the nonproteolipid phospholipid content of rachitic tissues, altering the relative proteolipid/phospholipid composition. Whereas proteolipids from normal tissue supportedin vitro calcification, proteolipids from rachitic tissues did not, indicating a direct effect of vitamin D on proteolipid structure. These data support the hypothesis that failure of rachitic cartilage to calcifyin vivo may be due in part to alterations in phospholipid and proteolipid metabolism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02405339
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Lectin-binding properties of the Merkel cell and other root sheath cells in perinatal rat vibrissae (1984)
    Springer
    Cell & tissue research 236 (1984), S. 373-381 
    Details
    ISSN: 1432-0878
    Keywords: Merkel cell surface ; Quinacrine fluorescence ; Lectins ; Vibrissae ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface carbohydrates on the Merkel cell of the outer root sheath (ORS) were investigated in 1to 4-day-old rat vibrissae by use of rhodamine isothiocyanate (RITC)-conjugated lectins. The red fluorescence of RITC provided a convenient assay for lectin binding to the Merkel cell, which is itself identified by its green fluorescence following selective uptake of the dye quinacrine. In monolayers or suspensions of freshly dissociated ORS cells, the Merkel cell showed high affinity for the α-fucose-specific lectin, Ulex europeus agglutinin I (UEA-I), thus revealing a novel feature for a basally located cell. Other high-affinity lectins included concanavalin A (Con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA), and Ricinus communis agglutinin I (RCA-I). In contrast, Dolichos biflorus (DBA), Bandeiraea simplicifolia I and II (BS-I and BS-II), and peanut agglutinin (PNA) virtually excluded the Merkel cell, though PNA-binding sites were unmasked after neuraminidase treatment. Other dispersed ORS cells had varying lectin affinities, and generally binding was inhibited by a competing haptenic sugar. The pattern of lectin binding seen in cryostat and paraffin sections of the vibrissa suggested that the Merkel cells share surface properties with their neighboring basal and/or spinous cells; however, unshared properties are likely to exist since ingrowing mechanosensory nerves recognize the Merkel cells, and not other epidermal cells, as their targets.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    Calcification initiation sites in the crab cuticle: The interprismatic septa (1984)
    Springer
    Cell & tissue research 236 (1984), S. 413-420 
    Details
    ISSN: 1432-0878
    Keywords: Calcification ; Crab cuticle ; Cell coat glycoprotein ; Carbonic anhydrase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In the crab cuticle the interprismatic septa (IS), which correspond to imprints left in the cuticle by the margins of the epidermal cells, penetrate the twisted structure of the chitin-protein matrix. The ultrastructure and geometric relationship between the fibrous architecture and the pattern of the prisms is described. The cytochemical characterization of the IS, by pronase treatment and ruthenium red staining, supports the hypothesis that this material corresponds to cell-coat glycoproteins released in the cuticle during secretion of the organic matrix. Calcification begins after ecdysis in the external laminae of the pigmented layer and along the IS. The presence of cation-binding glycoproteins in the sites where calcification is initiated could induce the nucleation of the mineral phase by concentrating calcium. The extracellular distribution of carbonic anhydrase, which favours carbonate deposition, is observed on ultrathin sections over the IS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214245
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Administration of caerulein to rats promotes antral epithelial cell renewal (1984)
    Springer
    Cell & tissue research 236 (1984), S. 711-715 
    Details
    ISSN: 1432-0878
    Keywords: Gastric antral mucosa ; Caerulein ; Gastrointestinal hormones ; Cholecystokinin ; Trophic effect ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The growth-promoting effect of caerulein on antral gastric mucosa was explored using Wistar rats. Implanted osmotic minipumps were used to administer submaximal doses of either caerulein or saline to normal rats for up to 4 days. In one group, reflux of bile and pancreatic juice into the stomach was avoided by previous surgical diversion of the distal common bile duct to the jejunum. DNA synthetic and mitotic activity in the antrum epithelium were estimated by 3H-thymidine pulse labelling and autoradiography during the administration of the peptide. The rate of cell migration was determined in animals killed 1, 2 and 3 days after the 3H-thymidine pulse. Administration of caerulein to normal rats provoked significant increases in both labelling and mitotic indices, and a significant acceleration of the upward cell migration in the glandular tubes. In the animals with distal diversion of bile and pancreatic secretions both labelling and mitotic indices were also increased over control values under the effect of the peptide. These data indicate that administration of caerulein stimulates cell proliferation in the antral gastric mucosa. This effect cannot be explained through increased reflux of pancreaticobiliary secretions in the stomach.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217242
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    Morphometric studies on lipid inclusions in Sertoli cells during the spermatogenic cycle in the rat (1984)
    Springer
    Cell & tissue research 236 (1984), S. 699-709 
    Details
    ISSN: 1432-0878
    Keywords: Testis ; Spermatogenic cycle ; Sertoli cell ; Lipid ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The volume and surface area of lipid inclusions often present in the cytoplasm of rat Sertoli cells was measured directly from semi-thin sections of perfusion-fixed testicular tissues using an image analyser linked to a light microscope. Sertoli cell nuclei were used as a reference for comparing any variations in the measured parameters of lipid inclusions during the rat spermatogenic cycle. Volume density of Sertoli cell lipid inclusions was assessed by morphometric analysis of Sertoli cells photographically reconstructed from electron micrographs. Maximum lipid content in Sertoli cells occurred during stages IX–XIV of the spermatogenic cycle, then declined at stages I–III and remained low from stages IV–VIII. The persistence and increase in number of many large Sertoli cell lipid inclusions beyond the stage where spermatid residual bodies are phagocytosed within the Sertoli cells (stage IX) suggests that the synthesis and lipolysis of Sertoli cell lipid inclusions represents an intrinsic functional cycle of the Sertoli cells. Stage-dependent variations in the lipid content of rat Sertoli cells offers morphological evidence that the metabolic duties of the Sertoli cells are synchronised with the spermatogenic cycle to provide local coordination of the proliferation and maturation of the germ cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    The ovarian follicle as a model for the cell-mediated control of tissue growth (1984)
    Springer
    Cell & tissue research 236 (1984), S. 717-724 
    Details
    ISSN: 1432-0878
    Keywords: Ovary ; Ovarian follicle ; Atresia ; Immunoregulation ; Immune tolerance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thy-1+ cells, producing Thy-1+ material, have been demonstrated by the indirect immunoperoxidase technique in the theca of growing ovarian follicles of the rat. OX-2 antigen, known as the minor glycoprotein of rat thymocytes, was detected in granulosa cells of non-growing follicles. Ia+ cells of dendritic type and/or activated macrophages were identified in the granulosa of advanced degenerating follicles, and remnants of the zona pellucida exhibited immunoglobulins. In some ovaries immunoglobulins were also bound to the zona pellucida of oocytes of early degenerating antral follicles. Medium-sized antral follicles with degenerating granulosa were occasionally invaded by cells carrying antigens of cytotoxic T lymphocytes or other T lymphocyte subsets, while degenerating large antral follicles were sometimes invaded by cells exhibiting antigen of cells with natural killer function (but not antigens of T lymphocytes). Granulosa cells of some degenerating antral follicles exhibited class-I antigens derived from the major histocompatibility complex. We suggest that cell-mediated control mechanisms of antigen expression and metabolism of tissue cells during their differentiation and degeneration should be considered in addition to the well-documented hormonal dependence of some tissues.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217243
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Glial cells in the pineal gland of mice and rats (1984)
    Springer
    Cell & tissue research 237 (1984), S. 245-252 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Interstitial cells ; Astrocytes ; Immunocytochemistry ; Rat ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Antigenic markers characteristic of astrocytes and their differentiative states (i.e., glial fibrillary acidic protein (GFAP), vimentin, and M1 and C1 antigens) were investigated in the pineal gland of mouse and rat using double immunolabeling techniques. In both species the socalled interstitial cells as characterized by TEM were shown to be astrocytes, since they expressed vimentin, but neither fibronectin (a marker for fibroblasts and endothelial cells) nor the neuron-specific L1 antigen or tetanus toxin receptors. Subpopulations of vimentin-positive pineal astrocytes were also GFAP- and C1- antigen-positive. M1- antigenpositive cells were not detected. It is concluded that a considerable proportion of interstitial cells in the pineal gland of rat and mouse are immature astrocytes which, in contrast to other parts of the central nervous system, persist into adulthood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217142
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Evidence for a role of the cytoskeleton in the in vitro folliculogenesis of the thyroid gland of the fetal rat (1984)
    Springer
    Cell & tissue research 237 (1984), S. 499-508 
    Details
    ISSN: 1432-0878
    Keywords: Thyroid gland, fetal ; Cytoskeleton ; Cytocha lasin B ; Vinblastine ; Colchicine ; Follicular development (thyroid) ; Tissue culture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thyrotropic hormone (TSH) or cAMP accelerate the formation of follicular cavities in the explanted thyroid gland of the 15-day-old rat fetus. Cytochalasin B or vinblastine and nocodazole or colchicine, which disorganize microfilamental and microtubular structures respectively, inhibit or completely block in vitro-induced folliculogenesis. Exposure of the thyroid tissue to lumicolchicine, a structural isomer of colchicine deprived of antimicrotubular activity, does not inhibit the activation of folliculogenesis induced by TSH. These results are strong evidence for the supposition that microfilaments and microtubules are involved in the TSH-stimulated mechanisms resulting in thyroid folliculogenesis. Folliculogenesis requires the integrity of both microfilaments and microtubules.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228434
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Immunohistochemical study on the development of CRF-containing neurons in the hypothalamus of the rat (1984)
    Springer
    Cell & tissue research 238 (1984), S. 539-544 
    Details
    ISSN: 1432-0878
    Keywords: CRF-neurons ; Hypothalamus ; Development, ontogenetic ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Appearance of immunoreactive corticotropin-releasing factor (CRF)-containing neurons was studied in developing hypothalamus of the rat by use of antisera against rat- and ovine CRF. These neurons were first recognized in the lateral and paraventricular nuclei on days 15.5 and 16.5 of gestation, respectively, when antiserum against rat CRF was employed. Antiserum against ovine CRF revealed the cells two days later exclusively in the latter nucleus. In both nuclei, the neurons increased in number with development. The neurons in the paraventricular nucleus appeared to project their immunoreactive processes to the median eminence via the periventricular and lateral pathways. In the median eminence, the immunoreaction with antiserum to rat CRF was first recognized in its anterior portion in the form of dots on day 16.5 of gestation but as beaded fibers in the external layer on day 17.5; these structures increased in amount with development in rostro-caudal direction. Although antiserum to ovine CRF was less potent in immunostainability than antiserum to rat CRF, it also revealed the beaded fibers in the median eminence on day 17.5 of gestation. Since evidence is available that the paraventricular nucleus is involved in corticotropin release, it is concluded that, in rats, the hypothalamic regulatory mechanism controlling the release of corticotropin initially appears on days 16.5–17.5 of gestation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219870
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Immunocytochemical demonstration of caldesmon (a calmodulin-binding, F-actin-interacting protein) in smooth muscle fibers and absorptive epithelial cells in the small intestine of the rat (1984)
    Springer
    Cell & tissue research 235 (1984), S. 207-209 
    Details
    ISSN: 1432-0878
    Keywords: Caldesmon ; Actin ; Immunocytochemistry ; Small intestine ; Smooth muscle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of caldesmon (a calmodulin-binding, F-actin-interacting protein) (Sobue et al. 1982) and of actin was studied in the rat's small intestine by means of light-microscopic immunocytochemistry. Positive immunostaining for caldesmon was seen in smooth muscle cells of the intestinal wall, and of blood vessels, and in the apical portion of the absorptive epithelial cells. The immunoreactivity in goblet cells was difficult to recognize. The positive reaction to immunostaining for actin showed almost the same pattern as that for caldesmon. These results suggest that this calmodulin-binding protein may play an important role in the control of actin-myosin interaction in smooth muscle cells and in non-muscle cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213742
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Internalization of ferritin-concanavalin A by the lactating mammary cell in vivo (1984)
    Springer
    Cell & tissue research 235 (1984), S. 433-438 
    Details
    ISSN: 1432-0878
    Keywords: Mammary gland ; Ferritin-concanavalin A ; Concanavalin A ; Endocytosis ; Membrane reuse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Ferritin-concanavalin A (Fer-Con A) was used to label the apical plasma membrane of the lactating cell to determine whether membrane internalization takes place. Rat glands were infused in vivo via the teat with 0.2 mg of Fer-Con A in 0.2 ml tris buffer (pH 7.0) containing 0.1% trypan blue, the latter acting as a marker of the infusate. Tissues were obtained from separate animals 5, 10 and 60 min postinfusion. Fer-Con A was seen in alveolar lumina bound to the outer surfaces of apical plasma membrane, microvilli and milk fat globules. It was observed within lactating cells on the inner membrane surfaces of endocytotic vesicles, Golgi cisternae, and secretory vesicles containing casein micelles, and in multivesicular bodies and lysosomes. Internalization of the ferritin-lectin conjugate into casein-containing secretory vesicles was detectable in the 5-min postinfusion tissue. Lysosomes were the only structures in control tissue that contained particles bearing some resemblance to Fer-Con A. The data provide evidence that apical plasma membrane is internalized and distributed to a number of intracellular compartments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217870
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Suprachiasmatic nucleus: Numbers of synaptic appositions and various types of synapses (1984)
    Springer
    Cell & tissue research 235 (1984), S. 449-452 
    Details
    ISSN: 1432-0878
    Keywords: Suprachiasmatic nucleus ; Morphometry ; Synapses ; Sexual dimorphism ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The suprachiasmatic nucleus (SCN) of male rats was estimated to contain 16×106 synaptic appositions (unilaterally) or 250×106 appositions in 1 mm3 tissue of the nucleus with an average of 1404 appositions per neuron. There are significantly fewer synaptic appositions in the suprachiasmatic nucleus of female rats (15×106 per SCN or 236×106 in 1 mm3 tissue of SCN with 1264 appositions per neuron on an average). Additionally, numbers of various types of synapses (axo-somatic, invaginated, dendrodendritic and optic) are estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217872
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Regional effect of monosodium-L-glutamate on the superficial layers of superior colliculus in rat (1984)
    Springer
    Cell & tissue research 235 (1984), S. 453-457 
    Details
    ISSN: 1432-0878
    Keywords: Monosodium-1-glutamate ; Neuropathology ; Rat ; Superior colliculus ; Toxicology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Systemic administration of monosodium-1-gluta-mate by single injections of 4 mg/g body weight in infant rats (2–10 days of age) results in acute swelling of cytoplasm and nuclear pyknosis of neurons in the stratum zonale and stratum griseum superficiale of the superior colliculus. Multiple daily doses of 4 mg/g body weight monosodium-1-glutamate result in an almost complete loss of neurons in these two superficial layers. The deeper layers appear not to be affected. No pathological effects were observed in the lateral geniculate body or pretectal complex. Light-and electron-microscopic studies reveal that the optic nerves are remarkably shrunken and many myelinated as well as unmyelinated axons are lost. Injection of 3Hproline into the vitreous body of one eye results in limited transport to the suprachiasmatic nucleus, lateral geniculate body and to lateral portions of the superior colliculus. The small percentage of intact axons in the optic nerve, as well as the limited proline transport from the eye, suggest that administration of monosodium-1-glutamate leaves intact some optic fibers, a portion of which belongs to the retinohypothalamic tract.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217873
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    Electron-microscopic demonstration of the distribution of calcium deposits in the exocrine pancreas of the rat after application of carbachol, atropine, cholecystokinin, and procaine (1984)
    Springer
    Cell & tissue research 235 (1984), S. 683-690 
    Details
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Calcium pool ; Calcium release ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226969
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Ontogenetic appearance of somatostatin-containing nerve terminals in the median eminence of rats (1984)
    Springer
    Cell & tissue research 236 (1984), S. 47-51 
    Details
    ISSN: 1432-0878
    Keywords: Somatostatin ; Ontogenesis ; Electron-microscopic immunohistochemistry ; Median eminence ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The development of immunoreactive (ir) somatostatin-containing nerve terminals in the rat median eminence (ME) has been examined electron-microscopically. Nerve fibers containing ir particles scattered throughout the axoplasm are first seen in the external layer of the ME on day 18.5 of gestation, and, on day 21.5 appear to terminate on the basement membrane of the perivascular space of the portal vessels. After birth, the fiber terminals contain several membrane-limited granules, which are labeled with ir PAP particles. Ultrathin, Epon-embedded sections of ME, treated by the protein A gold-labeling method for somatostatin, demonstrate positively labeled granules in the nerve fibers in the postnatal ME, but in the prenatal tissue, no specific gold-labeling is found. These findings show that, in the external layer of the ME, somatostatin storing occurs in the granules in the axonal terminals after birth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00216512
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    Identification of pericytes in the central nervous system by silver staining of the basal lamina (1984)
    Springer
    Cell & tissue research 236 (1984), S. 491-493 
    Details
    ISSN: 1432-0878
    Keywords: Brain vessels ; Basal lamina ; Pericytes ; Endothelial cells ; Glial cells ; Argyrophilic staining ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vibratome sections obtained from perfusion-fixed rat brains were stained by means of silver impregnation and physical development according to Gailyas (1970). Small pieces of the cerebral cortex were postfixed with buffered osmium tetroxide solution and processed for electron microscopy to examine the localization of the silver deposit at the cellular level. The cell surfaces of pericytes and smooth muscle cells were completely outlined by silver grains. Endothelial cells and perivascular astrocytes, however, showed an asymmetric distribution of the silver deposit, i.e., the deposit was restricted to the abluminal endothelial surface and to the astrocytic membrane adjacent to the vessel wall, respectively. The method allowed a clear-cut distinction between perikarya of endothelial cells and pericytes as well as glial cells in perivascular position, even at the light-microscopic level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214255
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Electron-microscopic study of silver staining of nucleoli in growing oocytes of rat ovaries (1984)
    Springer
    Cell & tissue research 236 (1984), S. 249-255 
    Details
    ISSN: 1432-0878
    Keywords: Oocyte ; Nucleolus ; Silver staining ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The nucleoli of dictyate-stage growing oocytes in rat ovaries were examined both with routine electron microscopy and electron microscopy after silver nitrate and ammoniacal silver nitrate (Ag-AS) staining. The nucleoli of the unilaminar follicular oocytes consist of twisted strands of dense fibrillar components, aggregates of granular components, and small fibrillar centers. After Ag-AS staining, silver grains are numerous on the dense fibrillar strands, fewer on the fibrillar centers, and very sporadic on the granular aggregates. The same stainability of three nucleolar components with the Ag-AS method was also confirmed in the nucleoli segregated by actinomycin D. During the transition of growing oocytes from bilaminar to plurilaminar follicle stage, the nucleolar dense fibrillar strands gradually conglomerate and are transformed into large and compact spherules. The stainability of dense fibrillar components with the Ag-AS method was lost along with this nucleolar transformation. These results may provide some new clues on the functional significance of AgAS-positive proteins in the nucleoli.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00214225
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    Independent development of presynaptic specializations in olfactory cortex of the fetal rat (1984)
    Springer
    Cell & tissue research 237 (1984), S. 103-109 
    Details
    ISSN: 1432-0878
    Keywords: Synapses ; Synaptogenesis ; Development fetal ; Olfactory cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy was used to study synaptogenesis in prepyriform cortex of fetal rat pups during early stages of synapse formation. Of special interest is the frequent occurrence of unapposed, developing synaptic specializations in axon and growth cone profiles. The location and morphology of the unapposed specializations suggests that thay are presynaptic in nature. These presumably immature presynaptic specializations are found in the lateral olfactory tract and subjacent cortex. Intermediate forms between uncontacted presynaptic specializations and definitive synapses suggest a synaptogenic sequence in which initial development of an immature presynaptic specialization begins without apposition of a postsynaptic element at that location. This implies that initiation of presynaptic development is not dependent upon postsynaptic contact and also raises the question of whether synaptic contacts could be established via presynaptic induction of postsynaptic formation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229204
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Connexon rearrangement in cardiac gap junctions: Evidence for cytoskeletal control? (1984)
    Springer
    Cell & tissue research 237 (1984), S. 185-186 
    Details
    ISSN: 1432-0878
    Keywords: Gap junction ; Cytoskeleton ; Heart ; Ultrarapid freezing ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using ultrarapid-freezing techniques and freezefracture electron microscopy, we report here a close association between cardiac gap junctions and specialized membrane domains containing regularly-spaced furrows. These specialized furrowed domains are observed only during periods of gap junction re-organisation (i.e., connexon redistribution) and may reflect the presence of underlying cytoskeletal elements controlling the position of connexons in the membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00229215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Transendothelial channels in fenestrated endometrial blood capillaries of rats (1984)
    Springer
    Cell & tissue research 237 (1984), S. 371-373 
    Details
    ISSN: 1432-0878
    Keywords: Endothelium ; Transport, intracellular ; Transport vesicles, channels ; Micropinocytosis ; Capillaries ; Endometrium ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Three types of transendothelial channels are described in the endothelium of blood capillaries in the endometrium of the rat. It is postulated that they may function as pores draining interstitial fluid to the venous blood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217160
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    Immunocytochemical demonstration of caldesmon and actin in thyroid glands of rats (1984)
    Springer
    Cell & tissue research 237 (1984), S. 375-377 
    Details
    ISSN: 1432-0878
    Keywords: Thyroid ; Immunocytochemistry ; Caldesmon ; Actin ; Endocytosis ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of caldesmon (a calmodulin-binding, F-actin interacting protein; Sobue et al. 1982) and actin was studied in the rat thyroid gland by means of light-microscopic immunocytochemistry, and the fine-structural distribution of actin filaments was examined by use of heavy meromyosin (HMM). Caldesmon and actin were demonstrated in the apical cytoplasm of almost all the follicle epithelial cells in normal as well as TSH-treated animals. Immunoreactivities for both caldesmon and actin showed almost the same pattern in localization. The smooth muscle cells of the blood vessels were also positive for caldesmon and actin. By electron microscopy, numerous actin filaments decorated by HMM and running perpendicularly or randomly to the apical surface were recognized in the apical cytoplasm of the follicle epithelial cell. These results suggest that caldesmon and actin, in conjugation with calmodulin, play a role in the regulation of cellular activity such as exocytosis and endocytosis in the apical portion of the follicle epithelial cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00217161
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Effect of monensin on the Golgi apparatus of absorptive cells in the small intestine of the rat (1984)
    Springer
    Cell & tissue research 235 (1984), S. 187-194 
    Details
    ISSN: 1432-0878
    Keywords: Golgi apparatus ; Monensin ; Small intestine ; Cytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effect of short-time treatment with the ionophore monensin, administered intraluminally at concentrations of 5 and 10 μM, was studied on the Golgi apparatus of absorptive cells in the small intestine of the rat. At 2–3 min after treatment most of the Golgi stacks exhibited dilated cisternae. At 4–5 min stacked cisternae were absent; they were replaced by groups of smooth-surfaced vacuoles. Dilatation and vacuolization occurred in the entire stacks without preferential effect on any particular Golgi subcompartment. Monensin did not influence the cytochemical Golgi reaction of thiamine pyrophosphatase and acid phosphatase. The characteristic staining pattern of these two enzymes in all Golgi cisternae of absorptive cells in the proximal small intestine, and the reactivity restricted to trans cisternae in distal segments of the small intestine, were unchanged after treatment with monensin. In the distal small intestine, the cytochemical pattern allowed the monensin-induced vacuoles to be attributed to the former cisor trans-Golgi face. Further, the cytochemical results demonstrate that vacuolization is not restricted to the stacked cisternae, but includes the trans-most cisterna. The latter, usually located at some distance from the Golgi stacks, has been defined as belonging to the GERL system in several types of cells. The clear response to monensin, an agent that selectively affects the Golgi apparatus, indicates common properties between trans-most and stacked Golgi cisternae.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00213739
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Alteration by estrogen of the nucleoli in nerve cells of the rat hypothalamus (1984)
    Springer
    Cell & tissue research 235 (1984), S. 485-489 
    Details
    ISSN: 1432-0878
    Keywords: Ventromedial nucleus ; Hypothalamus ; Ultra-structure ; Nucleoli ; Estrogen effects ; Chromatin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Estrogen is accumulated from the blood by nerve cells in the ventromedial nucleus of the hypothalamus and can facilitate female reproductive behavior by acting on this region of the brain. This cell group was examined in ovariectomized female rats, given estrogen or control treatment, by use of light and electron microscopy. A significantly greater portion of the nerve cells in the estrogen-treated animals had protuberances on their nucleolar surfaces, apparent under the light microscope. The fine structure of such protuberances included dense, aggregated material, which is shown to contain DNA by the sodium tungstate staining technique. Because increased numbers of such protuberances were found in nuclei of cells of the experimental group where previous studies demonstrated a significant increase in ultrastructural signs of biosynthetic activity, they may be associated with increased RNA synthesis. Thus, they could indicate, ultrastructurally, increased synthetic rates for RNA in nerve cells through which estrogen promotes reproductive behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226943
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Synthesis and transport of the organic matrix of the spicules in the gorgonian Leptogorgia virgulata (Lamarck) (Coelenterata: Gorgonacea) (1984)
    Springer
    Cell & tissue research 235 (1984), S. 533-538 
    Details
    ISSN: 1432-0878
    Keywords: Gorgonians ; Organic matrix ; Autoradiography ; Calcification ; Leptogorgia virgulata
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The sequence of the synthesis and transport of the organic matrix of spicules has been elucidated in the gorgonian Leptogorgia virgulata by use of 3H-aspartic acid as the tracer in electron-microscopic autoradiography. The entire process of matrix synthesis and transport takes approximately 2 h. It seems that the protein moiety of the organic matrix is synthesized in the RER prior to 5 min following the initial 10 min incubation in the tracer. At the 5 min chase the label is moving from the RER to the Golgi complexes where the carbohydrate moiety of the matrix is presumed to be synthesized. At the 5 to 15 min chases the label is transported out of the Golgi complexes via Golgi vesicles. This phase continues for 30 min. From 60 to 120 min the 3H-aspartic acid moves to the spicules. After 120 min the majority of the label has moved into the spicules. Silver grain counts over both multivesicular and electron-dense bodies remain at relatively low and constant levels over 4 h indicating that neither organelle is involved in the synthesis and transport of the organic matrix.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226950
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Karyometry of nuclei in liver cells (1984)
    Springer
    Cell & tissue research 235 (1984), S. 669-673 
    Details
    ISSN: 1432-0878
    Keywords: Liver-cell heterogeneity ; Hepatic venous branches ; Karyometry ; Binucleate cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In untreated adult male albino rats nuclear volume and the percentage of binucleate cells were determined in the first layer of hepatocytes adjacent to hepatic venous branches of varying diameters (〈40 μm, 40 μm–80 μm, 80 μm–120μm, 120 μm–160 μm, 〉160 μm), and in the third and fourth layer of hepatocytes in the remainder of the perivenous parenchyma. In the first layer of hepatocytes adjacent to the vascular structures means of nuclear volume are significantly lower and percentage of binucleate cells significantly higher than in the cells of the remainder of the perivenous parenchyma. Within each area measured distribution curves of nuclear volume classes were homogeneous but showed heterogeneity in comparison with each other. The morphometric data presented in this study strongly support the opinion of the heterogeneity of liver cells in the perivenous zone, as previously postulated on the basis of histochemical investigations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00226967
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...