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  • Rat  (39)
  • Pisum  (22)
  • Optimization
  • Springer  (64)
  • Blackwell Publishing Ltd
  • 1980-1984  (64)
  • 1965-1969
  • 1925-1929
  • 1980  (64)
Collection
Publisher
  • Springer  (64)
  • Blackwell Publishing Ltd
Years
  • 1980-1984  (64)
  • 1965-1969
  • 1925-1929
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Mathematical programming 19 (1980), S. 61-77 
    ISSN: 1436-4646
    Keywords: Optimization ; Nonlinear Programming ; Unconstrained Optimization ; Nondifferentiable Optimization ; Min—Max Problems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract In this paper, we suggest approximations for smoothing out the kinks caused by the presence of “max” or “min” operators in many non-smooth optimization problems. We concentrate on the continuous-discrete min—max optimization problem. The new approximations replace the original problem in some neighborhoods of the kink points. These neighborhoods can be made arbitrarily small, thus leaving the original objective function unchanged at almost every point ofR n . Furthermore, the maximal possible difference between the optimal values of the approximate problem and the original one, is determined a priori by fixing the value of a single parameter. The approximations introduced preserve properties such as convexity and continuous differentiability provided that each function composing the original problem has the same properties. This enables the use of efficient gradient techniques in the solution process. Some numerical examples are presented.
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  • 2
    ISSN: 1432-0827
    Keywords: Rat ; Calvarium ; Electron microscopy ; Preosteoclasts ; Osteoclasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary This is a study of the fine structure of cells of the 20-day fetal rat calvarium. Special attention is given to identifying and characterizing preosteoclasts. These cells are relatively common and located largely, but not exclusively, at the endocranial bone surface. The preosteoclasts are characterized by abundant mitochondria, an incomplete perinuclear Golgi apparatus, and variable-shaped dense granules. The dense granules are unique in appearance in that they contain an internal dense matrix surrounded by a clear halo. Most granules are circular in shape but some are elongate or tubular in form. Granules with identical appearance are observed in osteoclasts. The preosteoclasts are mononucleate, or occasionally binucleate. It is suggested that because preosteoclasts are morphologically distinctive and relatively abundant, it should be feasible to separate these cells from a heterogeneous cell isolate.
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  • 3
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    Calcified tissue international 32 (1980), S. 63-68 
    ISSN: 1432-0827
    Keywords: Rat ; Bone formation ; Fluorochrome ; Microphotometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary A method for quantitative studies of the formation rate of bone has been developed. After vital staining with calcein, the fluorescence of a bone section was measured with a microphotometer controlled by a mini computer. After staining the bone structure with alizarin red S in a second step, the section was measured in transmitted light. The two data sets were combined and the shortest distances between the bone surface and the fluorescence lines were computed. With this information the distance distribution and the bone area between the label and the surface could be calculated in two different ways: with the single labeling and the continuous labeling techniques. The advantages and disadvantages of the two methods are discussed and compared with those of other techniques.
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  • 4
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    Calcified tissue international 32 (1980), S. 113-122 
    ISSN: 1432-0827
    Keywords: Rat ; Bone ; Metaphysis ; Quantitative ; Aging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The purpose of this work was to analyze the proximal tibial metaphysis of the 170 g rat in a quantitative histologic fashion which would allow some relation to tissue age to be established. Stained 3 µm thick tissue sections were analyzed with the aid of a Merz grid on an eyepiece reticule and a light microscope. Tissue mass and cell distribution were studied in all areas. The rate of change in tissue mass during aging of the metaphysis was calculated. Two regions of the metaphysis were identified. One, corresponding to the primary spongiosa, less than 4.45 days of age, is a region of high turnover of hard tissue and high numbers of osteoblasts and osteoprogenitor cells. The other, corresponding to the secondary spongiosa, is a region of relatively low net tissue turnover and low numbers of osteoblasts and osteoprogenitor cells. Osteoclasts were found relatively more uniformly distributed through the metaphysis than were osteoblasts and osteoprogenitor cells. The rate of bone formation in the primary spongiosa is 50 times that found in the Haversian bone of the rib of 5-year-old humans and about 500 times that found at the cortical-endosteal surface of ribs of 5-year-old humans. It is argued that both cell distribution and tissue distribution in the metaphysis support the concept that osteoblasts and osteoclasts, rather than osteocytes, are responsible for the maturation of the metaphysis. The inhomogeneous distribution of both cells and tissue in the metaphysis has definite meaning for the interpretation of findings concerning the incorporation of radionuclides into the skeleton.
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  • 5
    ISSN: 1432-0827
    Keywords: Rat ; Hypophysectomy ; Dietary phosphorus deprivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The demands of growth are known to exacerbate the effect of phosphorus deprivation (PD). We examined whether changes associated with PD could be prevented in young rats in which growth and growth hormone (GH) were eliminated by hypophysectomy (HPX) and whether PD in normal intact rats (INT) was associated with increased secretion of GH. INT or thyroxine- and ACTH-replaced HPX rats were fed one of the three diets: 0.31% P (NP); 0.027% P (LP), and 0.31% P, pair-fed with LP-mates (NP-PF). The results indicate that HPX did not qualitatively alter several physiologic responses to PD: (a) serum and urinary phosphorus (P) decreased and urinary calcium (Ca) increased; (b) net intestinal Ca retention fell and duodenal sac uptake of45Ca rose; and (c) external P balance was restored and duodenal sac uptake of32P-phosphate increased. Only the hypercalcemia seen in INT, LP rats was prevented by HPX. In INT rats serum immunoassayable GH levels, measured in single samples, were not different between different dietary groups while pituitary bioassayable GH was reduced in both LP and NP-PF rats when compared to the NP rats. Thus, except for hypercalcemia, the physiologic responses associated with PD are not prevented by the elimination of growth and GH, and the development of these responses in INT rats was not associated with a consistent or specific alteration in GH secretion.
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  • 6
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    Planta 148 (1980), S. 437-443 
    ISSN: 1432-2048
    Keywords: Chloroplasts (number, DNA) ; DNA (chloroplast) ; Pisum ; Protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoplasts were prepared from pea (Pisum sativum L.) leaves throughout development and their contents spread in a monolayer to determine the number of chloroplasts per cell. This approach permitted the rapid analysis of more than 100 cells at each stage of development. The average number of chloroplasts per cell increased from 24±10 to 64±20 during greening and expansion of the first true foliage leaves; all cells containing chloroplasts apparently increase their chloroplast number. A parallel increase in the amount of DNA per nucleus was not observed. As the leaves senesced the chloroplast number gradually decreased to 44±12. We have correlated these changes with our previous results on the percentage of chloroplast DNA per cell. Chloroplast multiplication resulted in a 2.7-fold dilution (from 272 to 102) of the number of copies of the chloroplast DNA molecule per plastid.
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  • 7
    ISSN: 1432-2048
    Keywords: Ammonia assimilation ; Glutamate dehydrogenase ; Mitochondria ; Photorespiratory ammonia production ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ability of isolated pea-shoot mitochondria conditioned to incorporate ammonia into glutamate to reassimilate endogenously produced ammonia from glycine transformation was investigated. In the presence of 1 mM to 20 mM glycine less than 15% of the ammonia liberated was found to be incorporated into glutamate. Thus, a prominent role of mitochondrial glutamate dehydrogenase in the reassimilation of intramitochondrially produced ammonia can be excluded.
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  • 8
    ISSN: 1432-2048
    Keywords: Phytochrome ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The red-light(R)-absorbing form of phytochrome (Pr) was detected spectrophotometrically in a 20,000 g particulate fraction prepared from a 1,000 g supernatant fraction from epicotyl tissue of pea (Pisum sativum L.) seedlings grown in the dark and only briefly exposed to dim green light. The difference spectrum of phytochrome in this fraction was essentially the same as that of soluble phytochrome from the same tissue. When the non-irradiated 20,000 g particulate fraction was incubated in the dark at 25° C, an absorbance change (decrease) of Pr after actinic red irradiation was found only in the far-red (FR) region. When the 20,000 g particulate fraction was irradiated with R and then incubated in the dark, the FR-absorbing form of phytochrome (Pfr) disappeared spectrally at a rate about half that in the soluble fraction, and the difference spectrum of the Pr which became detectable after dark incubation of the 20,000 g particulate fraction was markedly distorted. In contrast, Pfr in a 20,000 g particulate fraction prepared from tissues irradiated with R did not change optically during dark incubation at 25° C for 60 min, while Pfr in the soluble fraction from the same tissue disappeared in the dark. No dissociation of either Pr or Pfr from the 20,000 g particulate fraction was indicated during a 60-min dark incubation at 25° C, but Pfr in a 20,000 g particulate fraction prepared in vitro from R-irradiated 1,000 g supernatant fraction in the presence of CaCl2 disappeared spectrally and the difference spectrum of Pr in the 20,000 g particulate fraction became quite distorted during the dark incubation.
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  • 9
    ISSN: 1432-2048
    Keywords: Auxin transport ; Cell length ; Light and auxin transport ; Phaseolus ; Pisum ; Transport (auxin)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The putative auxin-transporting cells of the intact herbaceous dicotyledon are the young, differentiating vascular elements. The length of these cells was found to be considerably greater in dwarf (Meteor) than in tall (Alderman) varieties ofPisum sativum L., and to be greater in etiolated than in light-grown plants ofP. sativum cv Meteor andPhaseolus vulgaris L. cv Mexican Black. Under given light conditions during transport these large differences in cell length did not influence the shapes of the transport profiles or the velocity of transport of14C-labelled indol-3yl-acetic acid (IAA) applied to the apical bud. However, in both etiolated and light-grown bean and dwarf pea plants the velocity of transport in darkness was ca. 25% lower than that in light. Under the same conditions of transport velocities in bean were about twice those observed in the dwarf pea. Exposure to light during transport increased the rate of export of14C from the labelled shoot apex in green dwarf pea plants but not in etiolated plants. The light conditions to which the plants were exposed during growth and transport had little effect on the rates of uptake of IAA from the applied solutions. The results indicate that the velocity of auxin transport is independent of the frequency of cell-to-cell interfaces along the transport pathway and it is suggested that in intact plants auxin transport is entirely symplastic.
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  • 10
    ISSN: 1432-2048
    Keywords: Cell-free translation ; Lectin ; Long-lived mRNA ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extracts prepared from dry pea (Pisum sativum, L; cv oberon) primary axes translate efficiently their endogenous messengers in an in vitro protein synthesizing system. The native long-lived messengers are biologically fully active and direct the synthesis of a whole range of polypeptides with MW ranging up to 130,000. About 0.5% of the total in vitro synthesized polypeptides are recovered in the immunoprecipitate obtained with pea lectin antiserum. Since about one-fourth of the radioactivity in the immunoprecipitate comigrates with authentic pea lectin it is concluded that about 0.1% of the long-lived messengers code for the lectin.
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  • 11
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    Planta 149 (1980), S. 427-432 
    ISSN: 1432-2048
    Keywords: Chloroplast envelope ; Light and chloroplast envelope ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Glutaraldehyde fixation in 0.33 M sorbitol without any buffer reveals changes in the staining properties of the envelopes of chloroplasts of pea plants kept in the light or in the dark prior to fixation. After dark pretreatment the outer double membrane of the chloroplast does not adsorb heavy metals, resulting in a “white” unstained rim instead of the usual membrane. All other membranes of the cell, including chloroplast grana, are not affected and stain normally. Light pretreatment of the plants allows the usual staining of the outer membrane of the chloroplats. Fixation carried out in the medium usually used to isolate intact CO2 fixing chloroplasts (sorbitol+buffer+ions) reverses the above process and results in unstained envelopes of chloroplasts from preilluminated leaves, while the envelopes of chloroplasts from leaves kept in the dark stain normally. Glutaraldehyde-fixed chloroplats isolated from preilluminated leaves show a very basic isoelectric point during electrofocusing, while fixed chloroplasts from predarkened tissue exhibit an isoelectric point at about pH 7.
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  • 12
    ISSN: 1432-2048
    Keywords: Embryo culture ; Enzyme-linked immunosorbent assay (ELISA) ; Legumin ; Pisum ; Protein (storage) ; Storage protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A highly sensitive immunoassay has been used for the detection of a major storage protein, legumin, in embryos of Pisum sativum L.; with this technique nanogram quantities could be measured. In the two varieties tested, legumin could be detected in embryos in vivo, when they had attained a fresh weight of 2·10-3 g and 3·10-3 g, respectively. Contrary to earlier claims, embryos cultured in vitro were shown to be capable of initiating legumin synthesis. This capacity to initiate legumin synthesis was confirmed by two-dimensional isoelectric focusing-electrophoresis and fluorography; embryos harvested before initiation of legumin synthesis and cultured in radioactive medium were shown to have synthesized legumin subunits. The amounts of legumin and total protein synthesized per unit fresh weight were consistently greater in vitro than in equivalent embryos grown in vivo.
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  • 13
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    Planta 150 (1980), S. 431-434 
    ISSN: 1432-2048
    Keywords: Auxin transport ; Electric current ; Pisum ; Potential gradients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When a d.c. potential of 9.0 V was applied to the stem of intact pea seedlings (Pisum sativum L. cv. Meteor and cv. Alderman) via 10 mM KCl-soaked filter paper electrodes placed ca. 50 mm apart the stem passed a steady current of 15–20 μA (resistance ca. 100 kΩ cm-1). The basipetal transport of [1-14C]IAA applied to the apical bud was completely inhibited over the portion of the stem through which current flowed and 14C-labelled compounds accumulated in the vicinity of the upper electrode. The inhibition of transport was independent of the polarity of the applied potential. The basipetal transport of IAA in the stem above the electrode was not affected. Labelled auxin accumulated at the upper electrode both as unchanged IAA and as a compound tentatively identified as indol-3yl-acetyl aspartic acid (IAAsp). These compounds were only slowly remobilised when the current was interrupted. However, the ability of the transport system to move freshly-applied IAA was rapidly and fully restored when the potential was removed. No injury to the plant was detected after maintaining a current flow for up to 72 h. No leakage of 14C-labelled compounds into the KCl solution bathing the electrodes was detected.
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  • 14
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    Planta 147 (1980), S. 444-450 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Cytokinin ; Decapitation ; Fruit-set ; Gibberellin ; Parthenocarpy ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The influence of removing the apical shoot and different leaves above and below the flower on the fruit-set of unpollinated pea ovaries (Pisum sativum L. cv. Alaska) has been studied. Unpollinated ovaries were induced to set and develop either by topping or by removing certain developing leaves of the shoot. Topping had a maximum effect when carried out before or on the day of anthesis, and up to four consecutive ovaries were induced to set in the same plant. The inhibition of fruit-set was due to the developing leaves and not to the apex. The third leaf above the first flower, which had a simultaneous development to the ovary, had the stronger inhibitory effect on parthenocarpic fruit-set. The application of different plant-growth regulators (indoleacetic acid, naphthylacetic acid, 2,4-dichlorophenoxyacetic acid, gibberellic acid, benzyladenine and abscisic acid) did not mimic the negative effect of the shoot.
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  • 15
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    Planta 147 (1980), S. 451-456 
    ISSN: 1432-2048
    Keywords: Abscisic acid ; Auxin ; Fruit-set ; Gibberellin ; Parthenocarpy ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of parthenocarpic fruits of Pisum sativum L. cv. Alaska was induced by the application of different plant-growth regulators in aqueous solution to the emasculated ovaries in untopped plants. At least one compound in each of the groups of auxins (2,4-dichlorophenoxyacetic acid), cytokinins (benzyladenine), and gibberellins (gibberellic acid) was found active. Gibberellic acid (GA3), however, was the only substance which produced pods similar to those of fruits with seeds. The length of the pods obtained by GA3 was a linear function of the logarithm of the concentration of GA3 in the solution. The effect of GA3 (at a concentration which produced 50% of the maximum pod length) was enhanced by a simultaneous application of 2,4-dichlorophenoxyacetic acid. Abscisic acid (ABA) counteracted the effect of GA3 and of topping. The results suggest that gibberellins and ABA may exert a major regulatory control in natural fruit-set. Peas can be used for the assay of fructigenic activity and is an advantageous material for the study of the mode of action of gibberellins on fruit-set.
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  • 16
    ISSN: 1432-2048
    Keywords: Legumin ; Pisum ; Protien synthesis ; RNA ; Storage protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Evidence is presented to show that legumin, the major storage protein in Pisum, is synthesised in vitro by the wheat germ and reticulocyte lysate systems, from polyribosomes and mRNA isolated from developing pea seeds. While legumin isolated from mature pea seeds consists of 40,000 and 20,000 MW subunits, the in vitro legumin is synthesised as a 60,000 MW precursor consisting of covalently linked 40,000 and 20,000 MW subunits. The implications of these findings are discussed in relationship to studies with other systems.
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  • 17
    ISSN: 1432-2048
    Keywords: Pisum ; Polyribosomes ; Post translational modifications ; Protein synthesis ; Storage proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Polypeptide material has been immunoprecipitated by antivicilin antibodies from translation products of polyribosomes and poly(A)-rich RNA isolated from developing seeds of Pisum sativum in the wheat germ and reticulocyte lysate cell-free synthesis systems. Analysis of this material by SDS-PAGE shows it to consist of three bands, of molecular weights 70,000, 50,000 and 47,000. The in vitro vicilin polypeptides of 70,000 and 50,000 mol. wt. have been shown to be very similar to the 70,000 and 50,000 mol. wt. subunits of vicilin by specific immunoprecipitation, and behaviour on treatment with cyanogen bromide and trypsin. The 50,000 mol. wt. in vitro vicilin polypeptide contains no significant extra sequence compared to the 50,000 mol. wt. vicilin subunit. The 47,000 mol. wt. in vitro vicilin polypeptide has no corresponding subunit in vicilin from mature seeds, but a 47,000 mol. wt. subunit is present in vicilin isolated from developing seeds. Comparison of translation products from polysomes isolated from seeds at middle and late stages of development shows that synthesis of the 50,000 and 47,000 mol. wt., but not 70,000 mol. wt. polypeptides is very much reduced at late stages of development. These results are discussed with reference to the nature of the vicilin fraction.
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  • 18
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    Planta 148 (1980), S. 346-353 
    ISSN: 1432-2048
    Keywords: Chromatin ; DNA ; Germination (embryos) ; Nucleosomes ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Micrococcal nuclease digestion of chromatin from ungerminated and 48 h-germinated pea embryos yields DNA fragments which are multiples of basic units of 194–195 base pairs. Extensive digestion produces a core particle of 145 base pairs. Deoxyribonuclease I gives rise to fragments which are multiples of 10 bases upon analysis on denaturing gels. These values are comparable with those found for other plant materials. These results indicate that gross changes in nucleosomal organization do not accompany the onset of germination.
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  • 19
    ISSN: 1432-2048
    Keywords: Gibberellin metabolism ; Pisum ; Seeds (gibberellin metabolism)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The metabolism of GA29 during seed maturation in Pisum sativum cv. Progress No. 9 was further investigated. [17-13C1]GA29 was metabolised to a GA-catabolite (structure 3), with incorporation of the [13C] label from the GA29 substrate into the GA-catabolite being demonstrated by GC-MS. Quantitation of the GA-catabolite using GC-MS was achieved by adding GA-catabolite, labelled with [18O], to seed extracts as an internal standard. At least 50% conversion of [13C1]GA29 to [13C1]GA-catabolite was demonstrated with the build up of exogenous [13C1]GA-catabolite strictly paralleling the accumulation of native GA-catabolite. These results strongly suggest that conversion of GA29 to the GA-catabolite is a natural metabolic step occurring during the final stages of seed maturation. 25 μg per seed of native GA-catabolite was recorded in 37 day old seeds. Some problems encountered in the analysis of extracts containing the GA-catabolite are discussed briefly.
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  • 20
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    Planta 148 (1980), S. 7-16 
    ISSN: 1432-2048
    Keywords: Glutamate dehydrogenase ; Glutamate formation ; Mitochondria ; Isoenzyme patterns ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A 2–8-fold increase in the activity of glutamate dehydrogenase (GDH), accompanied by an alteration of the GDH isoenzyme pattern, was observed in detached pea shoots floated on tap water (preincubated shoots). Sugars supressed the process, whereas NH + 4 and various metabolites as well as inhibitors of energy metabolism and protein synthesis were ineffective. The subcellular distribution pattern revealed evidence that the GDH isoenzymes are exclusively located in the mitochondrial matrix. The alterations in GDH activity occurring in preincubated shoots are restricted to the mitochondria. An experimental device suitable for studying the GDH function in isolated intact mitochondria has been established. Using [14C] citrate as the carbon source and hydrogen donor, the mitochondria synthesized considerable amounts of glutamate upon addition of NH + 4 . The rates of glutamate formation in dependency of increasing NH + 4 levels follow simple Michaelis-Menten kinetics. Half-saturation concentrations of NH + 4 of 3.6±1.2 mM; 1.9±0.06 mM and 1.6±0.1 mM were calculated for the mitochondria isolated from pea shoots, roots, and preincubated shoots, respectively. The results are discussed in relation to the possible role of GDH in NH+/4 assimilation at elevated intracellular NH+/4 levels.
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  • 21
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    Planta 150 (1980), S. 153-157 
    ISSN: 1432-2048
    Keywords: Manganese ; Pisum ; Superoxide dismutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A manganese-containing superoxide dismutase (EC 1.15.1.1) was purified to homogeneity from a higher plant for the first time. The enzyme was isolated fromPisum sativum leaf extracts by thermal fractionation, ammonium sulfate salting out, ion-exchange and gel-filtration column chromatography, and preparative polyacrylamide gel electrophoresis. Pure manganese superoxide dismutase had a specific activity of about 3,000 U mg-1 and was purified 215-fold, with a yield of 1.2 mg enzyme per kg whole leaf. The manganese superoxide dismutase had a molecular weight of 94,000 and contained one g-atom of Mn per mol of enzyme. No iron and copper were detected. Activity reconstitution experiments with the pure enzyme ruled out the possibility of a manganese loss during the purification procedure. The stability of manganese superoxide dismutase at-20°C, 4°C, 25°C, 50°C, and 60°C was studied, and the enzyme was found more labile at high temperatures than bacterial manganese superoxide dismutases and iron superoxide dismutases from an algal and bacterial origin.
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  • 22
    ISSN: 1432-2048
    Keywords: mRNA ; Protein synthesis ; Pisum ; Seeds (translation) ; Translation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extracts from the primary axes of dry pea (Pisum sativum L.) seeds are able to perform an initiation-dependent translation of exogenous mRNA. SDS polyacrylamide gel electrophoresis of the products synthesized under direction of alfalfa mosaic virus RNA (AMV-RNA) and tobacco mosaic virus RNA (TMV-RNA) shows that the fidelity of translation in this pea system is at least as high as in a wheat embryo cell-free protein synthesizing system. The endogenous messengers are also efficiently translated in extracts from the primary axes of pea seeds. The direct translation of these messengers in a homologous cell-free system may be of interest for a study of the products coded for by the long-lived messengers present in this plant.
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  • 23
    ISSN: 1432-2048
    Keywords: Amino acids (in chloroplasts) ; Chlorplast preparation ; Pisum ; Protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A procedure is described for the rapid (〈5 min) isolation of purified, physiologically active chloroplasts from Pisum sativum L. Mitochondrial and microbody contamination is substantially reduced and broken chloroplasts are excluded by washing through a layer containing a treated silica sol. On average the preparations contain 93% intact chloroplasts and show high rates of 14CO2 fixation and CO2-dependent O2 evolution (over 100 μmol/mg chlorophyll(chl)/h); they are also able to carry out light-driven incorporation of leucine into protein (4 nmol/mg chl/h). The amino-acid contents of chloroplasts prepared from leaves and from leaf protoplasts have been determined. Asparagine is the most abundant amino acid in the pea chloroplast (〉240 nmol/mg chl), even thought it is proportionately lower in the chloroplast relative to the rest of the cell. The chloroplasts contain about 20% of many of the amino acids of the cell, but for individual amino acids the percentage in the chloroplast ranges from 8 to 40% of the cell total. Glutamic acid, glutamine and aspartic acid are enriched in the chloroplasts, while asparagine, homoserine and β-(isoxazolin-5-one-2-yl)-alanine are relatively lower. Leakage of amino acids from the chloroplast during preparation or repeated washing was ca. 20%. Some differences exist between the amino-acid composition of chloroplasts isolated from intact leaves and from protoplasts. In particular, γ-aminobutyric acid accumulates to high levels, while homoserine and glutamic acid decrease, during protoplast formation and breakage.
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  • 24
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    Planta 148 (1980), S. 437-443 
    ISSN: 1432-2048
    Keywords: Chloroplasts (number, DNA) ; DNA (chloroplast) ; Pisum ; Protoplasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoplasts were prepared from pea (Pisum sativum L.) leaves throughout development and their contents spread in a monolayer to determine the number of chloroplasts per cell. This approach permitted the rapid analysis of more than 100 cells at each stage of development. The average number of chloroplasts per cell increased from 24±10 to 64±20 during greening and expansion of the first true foliage leaves; all cells containing chloroplasts apparently increase their chloroplast number. A parallel increase in the amount of DNA per nucleus was not observed. As the leaves senesced the chloroplast number gradually decreased to 44±12. We have correlated these changes with our previous results on the percentage of chloroplast DNA per cell. Chloroplast multiplication resulted in a 2.7-fold dilution (from 272 to 102) of the number of copies of the chloroplast DNA molecule per plastid.
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  • 25
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    Planta 150 (1980), S. 82-88 
    ISSN: 1432-2048
    Keywords: Legumin ; Pisum ; Protein (storage) ; Storage protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Since there is some question as to whether or not legumin is glycosylated, this storage protein was isolated by various procedures from developing cotyledons of Pisum sativum L. supplied with [14C]-labeled glucosamine and analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Legumin isolated by the classical method of Danielsson [(1949) Biochem. J. 44, 387–400] a procedure in which globulins extracted with a buffered salt solution are precipitated with ammonium sulfate (70% saturation) and legumin separated from vicilin by isoelectric precipitation, was labeled. The glucosamine incorporated into legumin was associated with low-molecular-weight polypeptides. In contrast, legumin isolated by the method of Casey [(1979) Biochem. J. 177, 509–520], a procedure where legumin is prepared by zonal isoelectric precipitation from globulins precipitated with 40–70% ammonium sulfate, was not labeled. However, the globulin fraction precipitated with 40% ammonium sulfate was labeled and the radioactive glucosamine was associated with low-molecular-weight polypeptides. Legumin isolated from protein bodies [Thomson et al. (1978) Aust. J. Plant Physiol. 5, 263–279] was not extensively labeled. However, the saltinsoluble fraction of protein body extracts was labeled and the radioactivity was associated with low-molecular-weight polypeptides. These results indicate that protein bodies contain a glycoprotein of low-molecular-weight that co-purifies with legumin isolated by the method of Danielsson but that is discarded when isolation methods developed more recently are used.
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  • 26
    ISSN: 1432-2048
    Keywords: Auxin ; Cell elongation ; Epidermis peeling ; Fusicoccin ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effects of peeling and wounding on the indole-3-acetic acid (IAA) and fusicoccin (FC) growth response of etiolated Pisum sativum L. cv. Alaska stem tissue were examined. Over a 5 h growth period, peeling was found to virtually eliminate the IAA response, but about 30% of the FC response remained. In contrast, unpeeled segments wounded with six vertical slits exhibited significant responses to both IAA and FC, indicating that peeling does not act by damaging the tissue. Microscopy showed that the epidermis was removed intact and that the underlying tissue was essentially undamaged. Neither the addition of 2% sucrose to the incubation medium nor the use of a range of IAA concentrations down to 10-8 M restored IAA-induced growth in peeled segments, suggesting that lack of osmotic solutes and supra-optimal uptake of IAA were not important factors over this time period. It is concluded that, although the possibility remains that peeling merely allows leakage of hydrogen ions into the medium, it seems more likely that peeling off the epidermis removes the auxin responsive tissue.
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  • 27
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    Cell & tissue research 205 (1980), S. 11-17 
    ISSN: 1432-0878
    Keywords: Pineal organ ; Subcommissural organ ; Vasopressin ; Oxytocin ; Vasotocin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vasopressin and oxytocin were specifically demonstrated in the rat brain using the unlabelled antibody-enzyme method and purification of the first antiserum. Vasopressin and oxytocin fibres extend via the subcommissural organ or habenular commissure into the pineal stalk and terminate in the anterior part of the pineal organ. In addition, immediately adjacent to the subsommissural organ many vasopressin-containing fibres run caudally toward the central grey. These results are discussed in relation to the proposed presence of vasotocin in the pineal gland.
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  • 28
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    Cell & tissue research 210 (1980), S. 167-170 
    ISSN: 1432-0878
    Keywords: Neuropeptides ; VIP-immunoreactive neurons ; Retina ; Amacrine cells ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Immunoreactive vasoactive intestinal polypeptide (VIP) was detected in a population of amacrine cells in the retina of the rat. Processes of these cells reach both the inner and outer half of the inner plexiform layer where they form sublayers. The VIP neurons are different from previously known amacrine cell types.
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  • 29
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    Cell & tissue research 210 (1980), S. 181-189 
    ISSN: 1432-0878
    Keywords: Catecholamines ; Neurophysin ; Simultaneous demonstration ; Functional interaction ; Rat
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    Topics: Biology , Medicine
    Notes: Summary A method was developed that allows the analysis of neuropeptides and monoamines in a single tissue section by the application of the unlabeled antibody method for peptide staining to tissue sections freeze-dried for formaldehyde-induced monoamine histofluorescence. The hypothalamic magnocellular system of male albino rats served as a model for this study; neurons were stained with anti-neurophysin sera, which mark the vasopressin- and oxytocin-associated proteins. Neurophysin-containing perikarya appeared to be surrounded by catecholamine-containing varicosities. This phenomenon was seen to varying degrees within the supraoptic and paraventricular nuclei. The juxtaposition of varicosities and peptidergic neurons suggests an afferent fiber-target neuron relationship that might favor a functional interaction between monoamines and neuropeptides.
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  • 30
    ISSN: 1432-0878
    Keywords: Rat ; Preovulatory follicle ; Ultrastructure ; Degeneration ; Atresia
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    Topics: Biology , Medicine
    Notes: Summary To identify and describe ovarian follicles committed to undergo follicular degeneration (atresia), immature rats were primed with pregnant mare serum gonadotropin (PMSG). After PMSG treatment, preovulatory follicles develop but subsequently degenerate. Prior to the appearance of pyknotic nuclei (Stage I of atresia), degenerative changes were observed in focal areas of the granulosa cell layer. These changes include “blebbing” of the cytoplasm and alterations in the shape of the granulosa cells. The appearance of these degenerative changes coincides with a decrease in ovarian concentrations of estradiol and testosterone. Since estrogens and androgens maintain the follicle, the decline in estradiol and testosterone could be responsible for the further degenerative alterations that lead to complete deterioration of the preovulatory follicle. In Stage I atretic follicles, lysosome-derived autophagic vacuoles develop and macrophages invade both the thecal and granulosa cell layers. The combined actions of the autophagic vacuoles and macrophages could destroy both the granulosa-cell and thecal layers and thereby transform the preovulatory follicle into an ovarian cyst.
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  • 31
    ISSN: 1432-0878
    Keywords: Lymph node ; Macrophages ; Postcapillary high endothelial venules ; Rat
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    Notes: Summary The afferent lymphatic vessels of rat popliteal lymph nodes were interrupted, and the histological alterations in the lymph nodes occurring 1 to 14 weeks after operation were studied. One week after operation the number of macrophages was considerably reduced and continued to decrease during the subsequent time periods studied. A 6 weeks most macrophages had disappeared. Simultaneously the immunological activity diminished and had completely disappeared 8 weeks after operation. Three weeks after operation the endothelial cells of the postcapillary high endothelial venules had flattened, and the number of immigrating lymphocytes was greatly reduced. Subsequently the lymph nodes became depleted of both macrophages and lymphocytes, leaving only the reticuloendothelial framework.
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  • 32
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    Cell & tissue research 209 (1980), S. 1-10 
    ISSN: 1432-0878
    Keywords: Myoepithelial cell ; Exocrine gland ; Scanning electron microscopy ; Rat
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    Topics: Biology , Medicine
    Notes: Summary By removing connective tissue components with enzymatic digestion followed by HCl-hydrolysis, myoepithelial cells (MECs) of the terminal portion in a variety of exocrine glands of the rat were examined with the scanning electron microscope. The profile of MECs varied considerably from gland to gland; MECs in the lactating mammary gland have a few long cytoplasmic processes in close contact with those of adjacent cells forming a continuous network around the terminal portion. Those of the exorbital lacrimal gland are stellate with many thin radiating processes with tapered ends that terminate freely. MECs in the sublingual gland are characterized by a number of broad and extensive cellular processes. MECs in the submandibular gland are similar in appearance to those of the exorbital lacrimal gland, but with more extensive cellular processes that form a more or less continuous network with those of the adjacent cells. No MECs were observed on the terminal portion of the parotid gland where the cells appear to be lodged on the intercalated duct. The relative surface area covered by MECs per terminal portion was also found to vary significantly, being 24% in the lactating mammary, 17% in the exorbital lacrimal, 48% in the sublingual, and 25% in the submandibular glands. The findings are discussed in relation to the physical properties of secretions in different glands.
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  • 33
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    Cell & tissue research 207 (1980), S. 89-107 
    ISSN: 1432-0878
    Keywords: Rehydration ; Nongranular vasopressin ; Intercellular clefts ; Axoplasmic reticulum ; Ultrastructural immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The vasopressin system of the rat was examined in the course of the first 12 h of rehydration after prolonged thirst at light and electron microscopic levels and by use of the peroxidase anti-peroxidase (PAP) method. Light microscopically, the median eminence was the only part of the system that not only displayed distinct differences between animals of different rehydration times but also showed a characteristic pattern of immunohistochemical reactivity in its rostro-caudal distribution. Ultrastructurally, in the perikarya a maximal labeling of the rough endoplasmic reticulum was observed after 2 h of rehydration, whereas an extensive labeling of the enlarged Golgi zones was attained after 4 h of resupplying water. A labeling of the intercellular clefts in the basal glial labyrinth of the supraoptic nucleus (and to a lesser degree in the subependymal neuropil adjacent to the paraventricular nucleus) was increased 30 min after the onset of drinking, as compared with water-deprived animals; it decreased slightly after 12 h of rehydration. The filling of the swollen fibers by increasing amounts of labeled axoplasmic reticulum, evident in the nuclear areas already after 30 min of water supply, begins in the median eminence after 2 h of rehydration and is fully developed after 4 and 8 h. Corresponding results hold true for the neural lobe but are somewhat delayed in comparison to the findings in the median eminence. The discussion considers (i) synthesis and transport of nongranular vasopressin within the axoplasmic reticulum, and (ii) release not only from the neural lobe but also from the nuclear areas and from the fibers of the median eminence.
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  • 34
    ISSN: 1432-0878
    Keywords: Neuronal grafting ; Dopamine ; Nigrostriatal system ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Dissociated cell suspensions were prepared from the substantia nigra of 15–17 day-old rat embryos and grafted via an intraparenchymal injection into the depth of the neostriatum of adult recipient rats. The survival and fibre outgrowth of the dopamine-containing neurones in the implants were studied by fluorescence histochemistry, and the functional capacity of the grafts was monitored by repeated testing of the amphetamine-induced turning behaviour of the implanted rats. Before transplantation the target neostriatum of the recipient rats was denervated of its normal dopaminergic innervation by an injection of 6-hydroxydopamine into the ipsilateral nigrostriatal dopamine pathway. The completeness of the denervation was ascertained by measurement of the intensity of the amphetamine-induced turning response. After injection of the dissociated cells large numbers of dopamine-containing neurones were found in clusters at the site of injection as well as scattered in the apparently intact neostriatal tissue up to a distance of about 0.5 mm from the site of injection. Extensive dopamine-containing fibre networks had developed around the implant. These newly formed fibres, which were most abundant around the cell clusters at the injection site, extended in a loose network into large areas of the initially denervated caudate-putamen. In all animals with surviving dopamine neurones the amphetamine-induced turning response was reduced, and in the most extensively reinnervated cases even reversed, within 3–5 weeks after transplantation. This strongly suggests that the implanted dopamine neurones are capable of restoring dopaminergic neurotransmission in the denervated neostriatum, probably via reinnervation of the denervated neostriatal tissue. The use of dissociated brain tissue preparations thus permits reliable intraparenchymal grafting of neurones to plausibly any desired site within the central nervous system, and should open entirely new possibilities for investigation of neuronal growth dynamics and functional reconstruction of damaged brain circuits, perhaps even in brains of larger mammals.
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  • 35
    ISSN: 1432-0878
    Keywords: Cardiac muscle cells ; Trabeculae carneae ; Fibrillar pattern ; Mouse ; Rat ; Rabbit
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    Topics: Biology , Medicine
    Notes: Summary The cardiac muscle fibers in the trabeculae carneae of mice, rats, and rabbits show a special arrangement of densely interwoven myofibrils. They cross at various angles; however, a preferred orientation of the fibrils cannot be discerned. It is suggested that due to this arrangement the myocytes of trabeculae are not able to contract to the same extent as ventricular myocytes, but thereby gain a high rigidity during contraction. Hence, they may play a principal role as “guiding ridges” for the flow of blood, thereby improving hemodynamics.
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  • 36
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    Cell & tissue research 209 (1980), S. 201-216 
    ISSN: 1432-0878
    Keywords: High pressure (2,100 bars) freezing ; Freeze-etching ; Nerve tissue ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Vitrification of biological specimens in liquid nitrogen can be achieved under high pressure (2,100 bars). This procedure obviates the use of aldehyde fixation and cryoprotection (glycerol). The present work demonstrates its applicability to the freeze-etching of mammalian brain tissue. Freeze-fracture replicas from rat cerebellar cortex and subfornical organ prepared by this method are compared to conventionally processed material using aldehyde fixation, glycerination and freezing with Freon. The formation of large ice crystals is prevented in tissue blocks up to 0.5 mm thick; deep etching is markedly enhanced. Cytoplasmic microstructures such as mitochondrial cristae, microtubules and microfilaments, are readily observable against a finely granulated cytosol matrix. An additional advantage is the combined application with freeze-substitution.
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  • 37
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    Cell & tissue research 206 (1980), S. 477-486 
    ISSN: 1432-0878
    Keywords: Synapse ; Synaptic cleft ; Aldehyde ; PTA technique ; Densitometry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Synaptic clefts of rat cerebral and cerebellar axodendritic spine synapses were studied after aldehyde-perfusion and subsequent immersion into osmic acid or after processing by the aldehyde-PTA technique. The threedimensional examination of aldehyde-perfused, osmic acid postfixed synapses revealed a double-layered intracleft lamina comparable in dimensions and position to the cleft density of non-osmicated, PTA-stained synapses. The relationship of this lamina to perisynaptic astroglial processes was pointed out. Densitometric analysis of the cleft area suggested the identity of the intracleft lamina of osmicated synapses with the cleft density of non-osmicated, PTA-stained synapses.
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  • 38
    ISSN: 1432-0878
    Keywords: Juxtaglomerular apparatus ; Sympathetic innervation ; Renin-angiotensin system ; Electron microscopy ; Fluorescence microscopy ; Tupaia belangeri ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It has previously been reported that the primitive primate Tupaia belangeri develops a renal failure when exposed to psychosocial stress. In order to learn if this high susceptibility to stress of the Tupaia kidney can be correlated with morphological and functional parameters of the Juxtaglomerular apparatus (JGA) and the renin-angiotensin system, comparative experiments were performed on Tupaia and rat. Our results reveal an outstandingly high potency of the JGA and the renin-angiotensin system in Tupaia as evident from the following findings: The Tupaia JGA contains a great number of epithelioid cells abounding in renin granules (electron microscopy). The renin content of the Tupaia kidney is considerably higher than in the rat (radio-immunoassay). The sympathetic innervation of the kidney and especially of the JGA is abundant in Tupaia (fluorescence and electron microscopy). Catecholamine contents of the kidney and other organs are significantly higher in Tupaia than in rats (spectrophotofluorometry). Our results support the previously developed concept of a potent intrarenal neuroendocrine interaction at the JGA level favouring, under certain conditions of social stress, the development of acute renal failure in Tupaia belangeri.
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  • 39
    ISSN: 1432-0878
    Keywords: Cerebellum ; Purkinje axon ; Ultrastructure ; Axotomy ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Transection of Purkinje cell axons in adult male rats made 1.5 mm or further from the cell body does not lead to the death of the neuron and results in compensatory structural alterations of the surviving axonal portions of the nerve cell. Near to, and at the emergence of recurrent collaterals of Purkinje cell axons, huge varicosities filled with filaments, granular material, lysosomes and mitochondria develop. Terminals of recurrent axon collaterals also exhibit different degrees of structural changes. Most striking of the morphological alterations is the regular presence of nematosomes in the hypertrophic axonal branches, especially in synaptic terminals. Since nematosomes were shown to contain RNA in other types of neurons, their presence in recurrent collaterals may indicate an enhanced synthetic activity in Purkinje axonal processes and endings after axotomy.
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  • 40
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    Cell & tissue research 213 (1980), S. 81-94 
    ISSN: 1432-0878
    Keywords: Interlamellar tight junctions ; Central myelin ; Myelogenesis ; Optic nerve ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The process of myelination in the central nervous system (CNS) of the rat (optic nerve) was studied with the freeze-fracturing technique and ultrathin sectioning to obtain information on the developmental mechanisms of interlamellar tight junctions. Using a tilting cartridge for analysis of thin sections, it could be demonstrated that during the initial phase of wrapping a tight junction formation develops between the joining tips of the oligodendrocytic process. In tannic acid-stained samples these junctions appear as typical quintuple-layered membrane fusions, while in potassium permanganate-stained material membrane thickenings between the apposing glial tips are prevalent. The latter configuration represents the characteristic feature of the so-called radial component of central myelin. Using the freeze-fracturing technique, a biphasic mode of the myelinic tight junction assembly was detected. It is suggested that tight junctions represent a prerequisite of the myelination process.
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  • 41
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    Plant and soil 56 (1980), S. 335-340 
    ISSN: 1573-5036
    Keywords: Acetylene reduction ; Field method ; Nitrogen fixation ; Non-destructive ; Pisum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Direct injection of acetylene into soil around plant roots, followed by determination of ethylene/acetylene ratios in the soil atmosphere has been tested as a rapid, non-destructive method of estimating acetylene reducing activity. In pots of artificial media as well as in field soil, the ratios determined within 10 min. after injection were significantly correlated with the rates of acetylenedependent ethylene production in detached roots. The method may be useful in preliminary screening of large numbers of plant-bacteria combinations.
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  • 42
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    Journal of optimization theory and applications 32 (1980), S. 463-478 
    ISSN: 1573-2878
    Keywords: Optimization ; control ; relativity ; stochastic processes ; wave mechanics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract The intention of this paper is to show how the influence of the work of Bellman has initiated a tentative new approach to quantum mechanics
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  • 43
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    Chromatographia 13 (1980), S. 61-67 
    ISSN: 1612-1112
    Keywords: Optimization ; Carrier gas velocity ; Gas chromatography ; Influence of temperature on optimum velocity
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    Topics: Chemistry and Pharmacology
    Notes: Zusammenfassung Die Wahl der mittleren, linearen Trägergasgeschwindigkeit bei der Analyse von Mehrkomponentengemischen unter isothermen und temperaturprogrammierten Bedingungen wird diskutiert. Es wird gezeigt, daß stets eine Trägergasgeschwindigkeit gewählt werden sollte, die mindestens gleich, besser jedoch höher ist, als die optimale Gasgeschwindigkeit für den ersten Peak, gemessen bei der Starttemperatur (Temperaturprogramm) oder bei der eingestellten Ofentemperatur (isotherme Fahrweise).
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  • 44
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    Cell & tissue research 205 (1980), S. 327-331 
    ISSN: 1432-0878
    Keywords: Somatostatin ; Cortical cells and fibers ; Immunohistochemistry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Using light microscopic immunohistochemistry, somatostatinpositive structures were observed in the cortex of the rat. These structures, including cells and fibers, are widely distributed in all cortical laminae and are also found in the basal ganglia. The positive results were obtained exclusively in two groups of animals sacrificed during two different months of two subsequent years. The reason for this variability in the immunocytochemical stainability of cortical structures remains enigmatic.
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  • 45
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    Cell & tissue research 205 (1980), S. 445-451 
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Rat ; Architecture
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    Notes: Summary The architecture of the pancreas was revealed by retrograde injection of the pancreatic ductal system of normal rats with a silicone rubber compound, and subsequent study of the preparation by light microscopy and scanning electron microscopy. The injected material became associated with both ducts and “acinar” areas. Examination of these specimens suggests that the arrangement of the exocrine pancreas is that of a complexly curving and branching system of tubules which anastomose and end blindly. This architecture, which is not that of a true acinar gland, provides a rational basis for the understanding of the simple dedifferentiative changes that accompany pancreatic carcinogenesis, and which have been generally interpreted as representing ductular proliferation.
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  • 46
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    Cell & tissue research 205 (1980), S. 453-471 
    ISSN: 1432-0878
    Keywords: Vasopressin system ; Postnatal development ; Ultrastructural immunocytochemistry ; Rat
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    Topics: Biology , Medicine
    Notes: Summary The present ultrastructural results indicate that, in the rat, the vasopressin-synthesizing perikarya of the supraoptic nucleus (NSO) attain a certain degree of maturity earlier than those of the paraventricular nucleus (NPV). In the neonate rat, the stainability of the nuclear areas is very weak; in the perikarya of the NSO a few labeled granules can be found, whereas the perikarya of the NPV often display only a labeled Golgi area, the cytoplasm being devoid of granules. At the end of the first (NSO) and the second (NPV) postnatal weeks, the filling of the neurosecretory granules with vasopressin is inhomogeneous with irregular spots of reaction product distributed on the granules. This feature is less obvious during the following week and has nearly disappeared after the third and fourth postnatal weeks. Already in the neonate two types of vasopressin-positive fibers are observed in the median eminence, characterized by the different diameters of their granules and by their typical location in the internal and the external pericapillary contact zone. Especially in one and two week-old animals, in the internal zone of the median eminence and, to a lesser degree in the neural lobe, the immunocytochemical reaction product is deposited on an axonal tubular network. Judging from the presence of very few vasopressin-negative fibers in the neural lobe of the neonate, the development of the oxytocin system appears to be delayed. A characteristic relationship between pituicytes and the neurosecretory fibers can be observed during the first two postnatal weeks. After the third postnatal week the immunocytochemical features of the vasopressin system correspond approximately to that in adult rats.
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  • 47
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    Cell & tissue research 206 (1980), S. 139-143 
    ISSN: 1432-0878
    Keywords: Pituitary cleft ; Scanning electron microscopy ; Cell surface changes ; Rat
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    Topics: Biology , Medicine
    Notes: Summary Scanning electron microscopy of the lining of the pituitary cleft was carried out in normal, lactating, castrated, adrenalectomized, and cyproterone-treated adult rats. Four cell types could be differentiated in the posterior wall in control and experimental animals: (1) cells with a smooth surface, (2) cells with microvilli located at the cellular borders, (3) ciliated cells, and (4) cells with evenly distributed microvilli. The anterior wall showed mainly cells with few microvilli located at their margins, and clusters of ciliated cells. In normal, and more frequently in experimental animals, the anterior wall showed shriveled cells, and variously sized cavities. Colloid appeared either as a network of finely granular material or as compact bodies adhering to the epithelial surface. These observations suggest that a compact component of the colloid is derived at least in part from degraded cells.
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  • 48
    ISSN: 1432-0878
    Keywords: AVT ; LHRH ; α-MSH ; Somatostatin ; Pineal Gland ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Resumé En utilisant des anticorps contre l'AVT, l'α-MSH, le LHRH et la somatostatine, des cellules épiphysaires du Rat ont été immunocytochimiquement colorées. Tous ces anticorps colorent les mêmes cellules. Ces cellules réagissent également quand un anticorps est utilisé contre la fraction épiphysaire UMO5R, fraction qui est douée de propriétés antigonadotropiques in vivo. Il a également été montré que le nombre des cellules immunoréactives était plus important dans la pinéale du jeune rat que dans celle de l'adulte. La comparaison des résultats obtenus avec différents anticorps et l'étude des propriétés de ces anticorps aprés absorption sur différents peptides ou sur différentes fractions épiphysaires, a permis de conclure que les réactions obtenues dans la pinéale du rat n'étaient que la conséquence d'une réaction croisée de ces anticorps avec une/des substance(s) inconnue(s) synthétisée(s) par la pinéale elle-même. La nature endocrine possible de cette substance qui serait chimiquement apparenté aux fractions épiphysaires Mouton UMO5R et Prot. 4, est discutée. Drs. B.L. Baker (Ann Arbor, Mich., USA), M.P. Dubois (Nouzilly, France), J. De Mey (Beerse, Belgium), J.D. Fernstrom (Cambridge, Mass., USA.), H. Goos (Utrecht, The Netherlands), B. Kerdelhué (Gif-sur-Yvette, France) and A.G.E. Pearse (London, U.K.) are also acknowledged for their gifts of various antibodies
    Notes: Summary Using antibodies against AVT, α-MSH, LHRH and somatostatin, immunoreactive cells were detected in the rat pineal gland. All of these antibodies stain the same cells, which also react immunocytochemically when an antibody against the UMO5R sheep pineal fraction, a fraction that presents antigonadotropic properties in vivo, is used. Relatively more immunoreactive cells are present in the pineals of young rats than in the pineals of adult animals. Comparison of the results obtained with different potent antibodies against each of the peptides, and a study of the staining properties of the antibodies in the pineal after solid phase adsorption to different peptides or to different sheep pineal fractions, led to the proposal that the immunoreactivity found in the rat pineal is not due to the presence of AVT, α-MSH, LHRH or somatostatin, but to a cross-reaction of each of these antibodies with (an) unidentified compound(s). This compound is synthetized in the pineal gland, as was demonstrated using cultured pineals. The UMO5R and the Prot. 4 fractions of the sheep pineal seem to be chemically related to this unknown compound, the possible endocrine nature of which is discussed.
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  • 49
    ISSN: 1432-0878
    Keywords: Sympathetic nerves ; Synaptic vesicles ; Noradrenaline ; Serotonin ; Pineal gland ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pineal gland of the rat receives a rich nervous supply originating from the superior cervical ganglia. These fibers contain serotonin in addition to their neurotransmitter, noradrenaline. Cytochemical studies at the ultrastructural level have shown that both amines are present in the cores of the granular vesicles that are characteristic of these nerves. It is presently shown that the bilateral electrical stimulation of the preganglionic fibers innervating the ganglia markedly reduces the number of small sites reacting cytochemically for both noradrenaline and serotonin, these sites corresponding to the cores of small granular vesicles, while the larger reactive sites (cores of large vesicles) remain unaltered. The vesicles are retained in nerve terminals after stimulation, as observed in conventionally processed tissues, although with altered sizes and shapes. Apart from these cytochemical and structural changes, nerve stimulation also reduces the endogenous noradrenaline content of the pineal gland. Thus, both noradrenaline and serotonin are released from their storage sites in pineal sympathetic nerves after electrical stimulation in vivo. This suggests the possibility that several substances with presumed transmitter or modulatory functions might be simultaneously released by nerve impulses from a given nerve terminal.
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  • 50
    ISSN: 1432-0878
    Keywords: Islet of Langerhans ; Aging ; Insulin-secreting cells ; Organ culture ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The B-cells of the endocrine pancreas constitute an adequate model for in vitro study of the aging process in highly differentiated cells. In the present study, collagenase-isolated islets of Langerhans from young and senescent rats were cultured up to 28 days. The response of the B-cells to the stimulatory conditions of the culture medium involved the nucleus, ribosomes, endoplasmic reticulum, Golgi apparatus, and secretory granules. Correlated data from light microscopy, electron microscopy, and insulin radioimmunoassay show that the differentiation and function of senescent B-cells are maintained in culture, as it has been proven for the B-cells of younger animals. On the other hand, signs of cytological deficiency not directly concerned with the specific function of B-cells were observed: abnormal mitochondria and lysosomes are more numerous in the senescent B-cells. The proliferative capacity of the B-cells of aged rats is reduced.
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  • 51
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    Cell & tissue research 207 (1980), S. 479-489 
    ISSN: 1432-0878
    Keywords: Horseradish peroxidase ; Primary afferent neurons ; Axonal transport ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The dynamics of horseradish peroxidase (HRP) transport in primary sensory neurons were studied in rats by demonstration of the reaction product in spinal nerves, spinal ganglia, dorsal roots and in the spinal cord at different survival times after application of the enzyme to the transected sciatic nerve and to the spinal cord. Using tetramethylbenzidine as the chromogen according to Mesulam (1978), transganglionic transport of HRP was shown in both the disto-proximal direction after peripheral application, and proximo-distal direction after central application. Significant differences in staining intensity between the central and peripheral processes of primary sensory neurons were found after all survival times used in this study. After peripheral application the number of labeled axons and the staining intensity were higher in spinal nerves than in dorsal roots; an inverse situation occurred after central application. These differences as well as the time sequences in staining of different parts of primary sensory neurons suggest that HRP applied to a peripheral nerve and to the spinal cord, respectively, enters the perikarya of spinal ganglion cells in any case before continuing its movement in a cellulifugal direction. Lysosomal degradation of the major portion of the applied HRP is supposed. However, in the post-perikaryal portion of a considerable number of neurons HRP-transport still occurs to a varying extent, thus resulting in labeling of nerve endings. In some neurons a post-perikaryal transport could not be detected light microscopically. The transport rates differ: the calculated transport rate of disto-proximal, cellulipetal movement in the fastest transporting neurons was 7.5 mm/h, that of the disto-proximal cellulifugal movement 2.5 to 3 mm/h.
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  • 52
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    Cell & tissue research 208 (1980), S. 253-259 
    ISSN: 1432-0878
    Keywords: Villus ; Caecum ; Postnatal development ; Rat ; Scanning electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The villi of the caecal mucosa in postnatal rats were studied using both scanning electron and light microscopy. On the day of birth, numerous villi of various sizes and shapes were present on the caecal mucosa. After the 5th day, the villi decreased very rapidly in length and in number. A strong constriction was observed at the basal region of the caecal villi. During postnatal days 5 ∼ 9 the villi probably separated and disappeared from the caecal mucosa. No villi were observed in rats that were over 10 days of age.
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  • 53
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    Cell & tissue research 209 (1980), S. 225-238 
    ISSN: 1432-0878
    Keywords: Tanycytes ; Median eminence ; Electron microscopy ; Rat ; Serum LH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The transport of hormones from the cerebrospinal fluid to the adenohypophysis by the tanycytes of the median eminence was examined in male rats. Electron microscopy revealed that all ependymal cells including the tanycytes disappear or degenerate in rats subjected to electric cauterization of the ependymal layer lining the third ventricle. However, the granular axons in the palisade layer of the median eminence remain intact. In rats subjected to electric lesion, no significant change was found in either the serum-LH level or in the weight of the adenohypophysis, testes, adrenal and thyroid glands. It is concluded that the tanycytes do not participate in the hypothalamic regulation of hypophysial function.
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  • 54
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    Cell & tissue research 209 (1980), S. 499-503 
    ISSN: 1432-0878
    Keywords: LHRH perikarya ; Aging ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The LHRH-synthesizing neuron system was studied in young proestrous and old female rats, and in aged ovariectomized or reserpine-treated females. The medial preoptic area and septal region of old animals contains more LHRH positive perikarya compared to that of young proestrous rats. Reserpine treatment moderately increases the number of immunostainable LHRH cells, while ovariectomy is ineffective in this respect.
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  • 55
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    Cell & tissue research 210 (1980), S. 33-45 
    ISSN: 1432-0878
    Keywords: Luliberin (LRF)-terminals ; Somatostatin-terminals ; Subfornical organ ; Neurohemal regions ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With the aid of light- and electron- microscopic immunocytochemistry, somatostatin- and luliberin (LRF)-positive fibers can be demonstrated in the rat subfornical organ (SFO). Each of the neurohormones has a specific location: LRF in the lateral parts of the organ, and somatostatin in the center of the posterior zone. Common to both neurohormone-containing fibers is the pattern in which they reach the organ as well as the fact that their terminals are located in the perivascular spaces of fenestrated vessels, i.e., within the limited neurohemal regions of the organ. Since injection of India ink of different colors demonstrates that the capillary bed of the SFO is connected with the central capillaries of the choroid plexus, the question arises as to whether the neurohormones released in the area of the SFO influence the choroid plexus.
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  • 56
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    Cell & tissue research 210 (1980), S. 283-294 
    ISSN: 1432-0878
    Keywords: Deep pineal ; Pineal complex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The results presented here reveal that in adult Sprague-Dawley and Wistar rats the pineal gland represents a complex rather than a single organ. Regularly one can distinguish (i) pineal tissue in the intercommissural region as a deep pineal, (ii) a superficial pineal, which represents the major part of the pineal complex, and (iii) nearly always a parenchymal stalk of variable length. The volume of the deep pineal with the adjacent parenchymal stalk exhibits great interindividual variation. It amounts to 127±39×105 μm3 (mean ±standard deviation). The histological appearance of the deep and superficial pineal tissue is fairly similar. The intrinsic cells of the deep and superficial pineal differ in nuances only. Karyometry reveals that the nuclear volumes of the intrinsic cells of the deep pineal are very variable ranging from 90–450 μm3, with a mean value of 207 μm3. The changes over a period of 24 h reach statistical significance.
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  • 57
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    Cell & tissue research 210 (1980), S. 333-337 
    ISSN: 1432-0878
    Keywords: Zona glomerulosa ; Angiotensin II ; Mitochondria ; Stereology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The effects of a chronic treatment with angiotensin II (up to 15 consecutive days) on the mitochondria of the rat zona glomerulosa cells were investigated by electron microscopic and stereological methods. Angiotensin induced a significant increase in the volume of the mitochondrial compartment. Up to the 3rd day of treatment this was due only to the hypertrophy of the organelles, and from the 3rd to the 15th day exclusively to mitochondrial proliferation. The hypothesis that angiotensin controls the growth and proliferation of rat zona glomerulosa mitochondria is discussed.
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  • 58
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    Cell & tissue research 211 (1980), S. 175-177 
    ISSN: 1432-0878
    Keywords: Parietal cell ; Stomach ; Circadian rhythm ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gastric parietal cells of rats maintained under standardized conditions and fed ad libitum were examined by electron microscopy at 6 time points of the 24-h day. Morphometric determinations were made on 4 cell characteristics. The volume density of secretory canaliculi was maximal at the mid-dark sampling point and decreased during the light phase; a secondary peak was seen 1 h before the onset of darkness. The surface density of microvesicles and RER fluctuated inversely with the pattern displayed by secretory canaliculi. The number of multivesicular bodies per cytoplasmic area exhibited a single peak, 1 h after the onset of darkness. It was further noted that parietal cells in the necks and bases of glands differed morphologically and that their organelle populations varied at individual circadian rates.
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  • 59
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    Cell & tissue research 211 (1980), S. 251-268 
    ISSN: 1432-0878
    Keywords: Somatostatin ; Luliberin (LRF) ; Intercellular clefts (brain) ; Immunoreactive glia-like cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary With the aid of electron microscopic immunocytochemistry following the application of antisera against somatostatin and luliberin (LRF), a labeling of the intercellular clefts in different areas of the brain was observed. This labeling is especially conspicuous near the basal pole of the cuboidal ependymal cells, but is also generally present in all regions containing neurohormone-producing perikarya or their processes (for example, the preoptic area, the basal ganglia and the cortex). Furthermore, in all these regions displaying labeled intercellular clefts, glialike cells and sparsely ciliated ependymal cells are found, the secondary lysosomes of which exhibit an immunoreactivity resembling that observed in the intercellular clefts. As sources of the immunoreactive material the following possibilities are discussed: (i) perikarya producing somatostatin or LRF, situated in the wall of the third ventricle and sending fibers between the cuboidal ependymal cells, (ii) hypothalamic and extrahypothalamic projections of both peptidergic systems, and (iii) in the case of somatostatin, immunoreactive perikarya in the cortex.
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  • 60
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    Cell & tissue research 211 (1980), S. 493-501 
    ISSN: 1432-0878
    Keywords: Hypothalamo-hypophysial system ; Rat ; Tanycytes ; Transport ; Ontogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Transport of ferritin and horseradish peroxidase from the 3rd ventricle to the median eminence was examined in rats during the perinatal life, the time when functional interrelations between hypothalamus and hypophysis are established. Protein tracers injected into the lateral ventricle are adsorbed on the apical surface of the tanycyte, mainly on its protrusions or in indentations. On the 18th day of prenatal life a few small bleblike protrusions are observed. After birth microvilli appear. In time their concentration increases to result in an increase of adsorbed substances. They are taken up by smooth and coated pinocytotic vesicles and transported to the basal portion of the cell or to the intercellular space bypassing junctional complexes. In addition to pinocytotic vesicles protein tracers fill channels of smooth ER or Golgi complex and multivesicular bodies illustrating a process probably involved in metabolic or secretory processes.
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  • 61
    ISSN: 1432-0878
    Keywords: Motoneurones ; Triceps surae muscle ; Retrograde labelling (Evans blue) ; Excitability ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Evans blue was injected into either the medial and lateral gastrocnemius or the soleus muscle of adult albino rats to mark retrogradely the corresponding motoneurones in the spinal cord. The labelled motoneurones were identified by the red fluorescence of their perikarya in the ventral horn of segments L4–L6. In addition, a monosynaptic reflex action potential was recorded only in the ventral roots L4–L6 after stimulation of the nerves to the medial and lateral gastrocnemius and the soleus muscle. Excitability and reflex latencies of labelled and unlabelled motoneurones of segments L4–L6 as well as the conduction velocities of their axons were measured. Apart from a small but statistically nonsignificant increase in excitability, no functional differences were found between labelled and control neurones. Thus, retrograde labelling of motoneurones with Evans blue prior to performing electrophysiological experiments has the advantage that the marked motoneurones can be identified under the fluorescence microscope without the need of additional staining or fixation.
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  • 62
    ISSN: 1432-0878
    Keywords: CRF ; Vasopressin ; Adrenalectomy ; Rat ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In female Wistar rats the influence of adrenalectomy and NaCl administration on the amount of “classical” neurosecretory material (cNSM) in the supraoptico-hypophysial system and on vasopressin-like substance-containing granules (vlG) in the outer layer of the median eminence has been studied. In conjunction with appropriate sodium replacement, adrenalectomy induces an increase in the amount of vlG but does not alter the amount of cNSM. Administration of hypertonic saline diminishes cNSM but has no or only little influence on the amount of vlG. From the findings it is concluded that cNSM and vlG, in spite of their identical histochemical and immunohistochemical properties, have different functions. The functional significance of the vlG is discussed.
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  • 63
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    Cell & tissue research 212 (1980), S. 443-455 
    ISSN: 1432-0878
    Keywords: LRF-immunoreactive perikarya ; Preoptic area ; Light and electron microscopic immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary At the light microscopic level, following immunostaining with a single antiserum against luliberin (LRF), two types of hormone-producing perikarya in the preoptic area are demonstrated. The two cell types differ in their morphological features: a bipolar, smooth-contoured cell type can be differentiated from an irregularly contoured unipolar type. Intermediate forms between both cell types occurring in the same area are not observed. Electron microscopically, both cell types contain labeled granules of similar size and immunoreactivity. It is dicussed whether the uneven surface of the one cell type is due to areas of synaptic contacts, and whether both cell types are integrated in different neuronal and functional circuits. Moreover, at the ultrastructural level, from the irregularly contoured LRF-producing perikarya a further positively stained cell type, probably a glial cell, can be differentiated. The specific labeling of the latter is caused by its content of immunoreactive lysosomal bodies. Differentiation between the labeled glial cells and the irregularly contoured LRF-producing perikarya is not possible at the light microscopic level.
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  • 64
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    Cell & tissue research 212 (1980), S. 457-464 
    ISSN: 1432-0878
    Keywords: Somatostatin immunoreactivity ; Cortex ; Hypothalamus ; Light and electron microscopic immunocytochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using an antibody against somatostatin (antiserum “F”), two somatostatin-immunoreactive systems, (i) a hypothalamic and (ii) an extrahypothalamic cortical system, are demonstrated in the rat. Another antiserum raised against somatostatin (antiserum “BS 102”) stains only the axons but not the perikarya of the hypothalamic system; the cortical somatostatin system does not react with this antiserum. The electron microscopic findings do not allow decision whether the above-mentioned hypothalamic and cortical neurons possess a common prohormonal form of somatostatin, immunoreactive only with antiserum “F”. They show, however, that the granules in both neuronal systems differ considerably; in the cortical neurons they measure approximately 65 nm in diameter, in the hypothalamic neurons 90–120 nm in diameter. Thus, both somatostatin systems are different and independent from one another.
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