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  • Rat  (80)
  • Springer  (80)
  • 2015-2019
  • 1980-1984  (80)
  • 1925-1929
  • 1983  (36)
  • 1981  (44)
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  • Springer  (80)
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  • 2015-2019
  • 1980-1984  (80)
  • 1925-1929
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  • 1
    Digitale Medien
    Digitale Medien
    Cytochemical studies on the ferritin-containing vesicles of the rat incisor ameloblasts with special reference to the acid phosphatase activity (1981)
    Springer
    Calcified tissue international 33 (1981), S. 51-55 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Rat ; Incisor ; Amelogenesis ; Acid phosphatase ; Ferritin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Acid phosphatase was localized in rat incisor ameloblasts without prior decalcification. Whenβ-glycerophosphate was used as the substrate, an intense reaction was observed in the supranuclear region of the secretory ameloblasts. But the reaction was dramatically reduced at the transitional stage and was very weak in the maturation ameloblasts. Whenp-nitrophenylphosphate was the substrate, the reaction product was consistently seen in the Golgi cisternae and the vesicular components of the ameloblasts at all stages of enamel development. These observations suggest that there are two acid phosphatases in ameloblasts. One is in the secretory ameloblasts and the other in the transition and maturation ameloblasts. X-ray micro-analyses for Fe and Pb showed that Fe and acid phosphatase were in the ferritin-containing vesicles at the later stage of enamel maturation. This evidence suggests that ferritin is digested in these vesicles for the release of the Fe pigment to the enamel. An increase in the number of intercellular bridges between ameloblasts was correlated with the dramatic decrease in height of ameloblasts at the pigment release stage. The ameloblast membranes were acid phosphatase positive at the intercellular bridges whenp-nitrophenylphosphate was the substrate. This activity may be involved in the reduction in the surface area of the ameloblast membranes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02409412
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  • 2
    Digitale Medien
    Digitale Medien
    Oral 1,25(OH)2D3: An effective prophylactic treatment for glucocorticoid osteopenia in rats (1983)
    Springer
    Calcified tissue international 35 (1983), S. 107-110 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Calcium ; Glucocorticoid ; Vitamin D ; Osteoporosis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Eighty-eight adult male Sprague-Dawley rats were given a diet with either (a) 0.5% Ca and 0.6% P or (b) 0.01% Ca and 0.6% P. Osteopenia was created by adding prednisolone to the diet. The prophylactic effect of oral 1,25(OH)2D3 on the osteopenia was studied. It was found that prednisolone osteopenia in the rat was associated with defective Ca absorption. By giving an oral dose of 1,25(OH)2D3, it was possible to maintain normal Ca absorption during prednisolone treatment and to prevent the bone loss. No significant hypercalcemia or any kidney calcifications were seen. These results are in contrast to earlier findings, in which subcutaneous administration of 1,25(OH)2D3 failed to prevent prednisolone osteopenia because of its tendency to increase bone resorption.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02405014
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  • 3
    Digitale Medien
    Digitale Medien
    Effect of vitamin D deficiency on urinary excretion of connective tissue derivatives (hydroxyproline and glycosaminoglycans) in rats (1981)
    Springer
    Calcified tissue international 33 (1981), S. 177-180 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Connective Tissue ; Vitamin D deficiency ; Hydroxyproline excretion ; Glycosaminoglycan excretion ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The urinary excretion of two connective tissue metabolites was studied in both control and vitamin D deficient rats. Hydroxyproline (HyPRO) excretion was determined after 2, 13 and 22 months (experiment I). It decreased with aging in animals receiving the control diet. On the contrary, this excretion increased as a function of age in vitamin D deficient animals. At the age of 22 months, HyPRO excretion was respectively 31 and 1708 µg a day in control and deficient animals. HyPRO and glycosaminoglycans (GAG) excretion was measured on a group of both control and vitamin D deficient rats at the age of 21 months (experiment II). These results confirm the high excretion of HyPRO in deficient animals. On the contrary, the GAG excretion was higher in control animals than in deficient ones, the mean excretion being respectively 412 and 234 µg a day.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02409432
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  • 4
    Digitale Medien
    Digitale Medien
    Effects of chronic protein deficiency on skeletal development of young rats (1981)
    Springer
    Calcified tissue international 33 (1981), S. 223-231 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Protein deficiency ; Bone formation ; Skeletal development ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Protein deficiency was produced by freely feeding young rats a 1% lactalbumin diet for 12 weeks in order to study the effects of protein-calorie malnutrition on skeletal development. During the experiment the food and caloric intake and weight of the experimental animals decreased, while those parameters of the control animals progressively increased. However, when gross caloric intake was expressed as a function of the metabolic size of the animal, the caloric consumption was similar for both groups of animals. The protein-deficient animals exhibited micro-radiographic and histological features of an abnormal pattern of endochondral bone formation. Appositional bone growth, as determined by the daily appositional rate and the percentage of endosteal surfaces undergoing active bone formation, was significantly decreased in these animals, as was the percentage of periosteal surfaces exhibiting resorption. Both chemical analyses of the whole bone and electron probe microanalysis in the specific area of actively calcifying bone revealed no significant differences between the mineral content of control and protein-deficient animals. This study distinguishes the effects of protein deficiency from that of combined protein-calorie deprivation and demonstrates that the abnormal skeletal development observed was the result of a decrease in the quantity of bone formed rather than an altered mineral content.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02409441
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  • 5
    Digitale Medien
    Digitale Medien
    Elastic fibers associated with collagenous fibrils surrounded by reticular cells in lymph nodes of the rat as revealed by electron microscopy after orcein staining (1981)
    Springer
    Cell & tissue research 220 (1981), S. 445-448 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Lymph node ; Reticular cell ; Reticular fiber ; Elastic fiber
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Electron microscopy of the rat lymph node disclosed reticular cells in close association with bundles of collagenous fibrils 30–45 nm in diameter, and electron lucent “amorphous” substances surrounded by microfibrils 11 nm in diameter, with junctional complexes. The amorphous substances, distinctly revealed by orcein staining, and the microfibrils showed morphological characteristics of elastic fibers. Since elastase digestion of 2% glutaraldehyde fixed specimens induced the selective disappearance of the orcein-stainable substances, it was concluded that they are elastin. Elastin often had a close contact with the plasma membrane of reticular cells. It is suggested that reticular cells synthesize elastic fibers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210522
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  • 6
    Digitale Medien
    Digitale Medien
    Electron microscopic study of immunoreactive LHRH perikarya with special reference to neuronal regulation (1981)
    Springer
    Cell & tissue research 220 (1981), S. 511-518 
    Details
    ISSN: 1432-0878
    Schlagwort(e): LHRH neuron ; Synapse ; Immunohistochemistry ; Electronmicroscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In early postnatal rats, immunoreactive LHRH perikarya in the preoptic area were studied by light and electron microscopy. Synaptic junctions were found between the immunoreactive perikaryon or its process, and the immunonegative nerve fibers. The significance of these synapses is discussed in relation to possible mechanisms by which the activities of LHRH neurons are regulated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216754
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  • 7
    Digitale Medien
    Digitale Medien
    Autoradiographic localization of 3H-GABA uptake in the thyroid gland of the rat (1981)
    Springer
    Cell & tissue research 220 (1981), S. 873-879 
    Details
    ISSN: 1432-0878
    Schlagwort(e): γ-Aminobutyric acid (GABA) ; Autoradiography ; Thyroid gland ; Transport ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The uptake of γ-aminobutyric acid (GABA) in the thyroid gland of the rat was studied autoradiographically following in vitro incubation. High-affinity GABA uptake was localized in follicle cells, whereas C cells (parafollicular cells) in general did not accumulate GABA by high-affinity transport. The follicle cells were also the main sites of low-affinity GABA uptake. Additionally, some nerve fibres were found to accumulate GABA. The predominant localization of GABA uptake in follicle cells is discussed in view of a presumed role of GABA in thyroid function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210468
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  • 8
    Digitale Medien
    Digitale Medien
    Comparative studies of quinacrine-positive neurones in the myenteric plexus of stomach and intestine of guinea-pig, rabbit and rat (1981)
    Springer
    Cell & tissue research 221 (1981), S. 93-107 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Quinacrine ; Myenteric plexus ; Non-adrenergic, non-cholinergic nerves ; Guinea-pig ; Rabbit ; Rat ; ATP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The number of quinacrine-fluorescent nerve cell bodies and the percentage of the ganglion area occupied by this fluorescence within stretch preparations of the myenteric plexus of the stomach and ileum of the guineapig, rabbit and rat were assessed. The number of quinacrine-positive cell bodies per cm2 of plexus varied between 1045 in the rabbit ileum to 2633 in the rat stomach, whilst the percentage of the ganglionic area occupied by fluorescence was approximately 10 %. The distribution of quinacrine-fluorescent nerve fibres and cell bodies in the myenteric plexus was compared to the distribution of nerves revealed by catecholamine fluorescence and by staining for acetylcholinesterase in the stomach and ileum of all three species. Quinacrine fluorescence appears to be selective for non-adrenergic, non-cholinergic nerves; the possibility that it binds to high levels of ATP is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216573
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  • 9
    Digitale Medien
    Digitale Medien
    Intercellular channels in the pars tuberalis of the rat hypophysis and their relationship to the subarachnoid space (1981)
    Springer
    Cell & tissue research 218 (1981), S. 345-354 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypophysis ; Pars tuberalis ; Intercellular channels ; Subarachnoid space ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A system of intercellular channels is described in the pars tuberalis (PT) of the female rat. These spaces are lined by all types of cells found in the PT and are not sealed off by tight junctions. Ventrally and dorsally, the intercellular spaces open toward the basement membranes separating the PT from (i) the subarachnoid space, and (ii) the perivascular space of the portal capillaries, respectively. These intercellular channels differ from the follicles, which are also found in the PT, being lined by a particular type of cell. In a second group of female rats an epoxy mixture was injected into the third ventricle; 10 min thereafter horseradish peroxidase was infused into the cisterna magna. After processing the brain for the demonstration of exogenous peroxidase, it was found that the tracer had reached the subarachnoid space adjacent to the hypothalamus and entered into all ventricular cavities with the exception of the infundibular recess. Under these experimental conditions it was found that the tracer fills all intercellular channels of the PT, thus indicating that there is no barrier between the subarachnoid space and the PT. It is suggested that the subarachnoid space should be regarded as a probable route for the transport of trophic factor(s) and/or secretory product(s) of the PT.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210349
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  • 10
    Digitale Medien
    Digitale Medien
    Cells capable of uptake of horseradish peroxidase in some circumventricular organs of the cat and rat (1981)
    Springer
    Cell & tissue research 219 (1981), S. 85-92 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Circumventricular organs ; Reticuloendothelial system ; Phagocytic cells ; Horseradish peroxidase ; Cat ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structure of mesenchymal cells distributed in some of the “hypendymal organs” of the circumventricular system in the cat and rat was demonstrated after intravenous injection of high doses of horseradish peroxidase. These cellular elements were observed in the vicinity of blood vessels of the organon vasculosum laminae terminalis, subfornical organ and area postrema. Electron-microscopically, these cells located between the basal laminae of the brain parenchyma and the blood capillaries show long cellular processes encircling fenestrated capillaries. Light and electron-microscopic examination revealed that this cell type is identical with the “horseradish peroxidase-uptake cells”, previously reported in the vicinity of the hypophysial portal system. Such phagocytic cells may be considered as a cellular component intervening between the brain parenchyma and the blood stream, playing a role in selective barrier functions in the above-mentioned circumventricular organs where a blood-brain barrier in the classical sense of the definition is lacking.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210020
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  • 11
    Digitale Medien
    Digitale Medien
    Glycogen accumulation in the parathyroid gland of the rat after fluoride ingestion (1981)
    Springer
    Cell & tissue research 220 (1981), S. 125-130 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Glycogen ; Parathyroid gland ; Fluoride ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The parathyroid glands of young male rats given 150 ppm fluoride in their drinking water for 10 weeks were examined by transmission electron microscopy. As a result of fluoride ingestion, the parathyroid chief cells of the experimental animals accumulated glycogen in excess of that seen in control animals given distilled drinking water for the same time period. In the majority of active chief cells, glycogen granules were diffusely spread throughout the cytoplasm as single granules or in small deposits. Large aggregations of glycogen granules were also seen within intercellular spaces. Accompanying the increase in glycogen was a rise in the number and development of the organelles associated with protein synthesis and secretion. The accumulation of glycogen is similar to that in hyperparathyroidism caused by chronic stimulation and prolonged secretory activity of the parathyroid gland. The results of this study suggest that increased amounts of glycogen occur in hyperactive chief cells of the parathyroid in response to the ingestion of large doses of fluoride.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209971
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  • 12
    Digitale Medien
    Digitale Medien
    Morphometric analysis of the autophagic and crinophagic lysosomal systems in mammotropes throughout the estrous cycle of the rat (1981)
    Springer
    Cell & tissue research 220 (1981), S. 131-137 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Adenohypophysis ; Mammotropes ; Autophagic and crinophagic lysosomes ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The crinophagic and autophagic lysosomal systems were studied in mammotropes (prolactin secreting cells) of the adenohypophysis throughout the estrous cycle of the rat. By means of morphometric analysis, it was found that the volume of secondary autophagic lysosomes was usually greater than that of the crinophagic type. Although the volumes of both secondary autophagic and crinophagic lysosomes were minimal throughout proestrus and diestrus 2, the autophagic lysosomal volume per mammotrope was elevated during the estrous period. The volume of secondary crinophagic lysosomes per mammotrope increased during late estrus and remained elevated throughout early diestrus 1. Furthermore, there was an inverse relationship between the volume of mature secretory granules per cell and of the crinophagic system. These data suggest a role for lysosomes in the regulation of synthesis and secretion of prolactin by the adenohypophysis of the rat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209972
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  • 13
    Digitale Medien
    Digitale Medien
    The cell coat of the olfactory epithelium proper and vomeronasal neuroepithelium of the rat as revealed by means of the Ruthenium-red reaction (1983)
    Springer
    Cell & tissue research 230 (1983), S. 139-146 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Vomeronasal neuroepithelium ; Olfactory epithelium proper ; Cell coat ; Ruthenium red ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The apical cell coat of the olfactory epithelium proper and the vomeronasal neuroepithelium of the rat was investigated electronmicroscopically by means of the Ruthenium-red reaction. In the olfactory epithelium proper, the cilia of receptor cells and microvilli of supporting cells possess a cell coat measuring approximately 10 nm in thickness. In the vomeronasal neuroepithelium, the apical cell coat is thicker than in the olfactory epithelium proper. On microvilli of vomeronasal receptor cells the cell coat varies in thickness from 15 to 20 nm, and on microvilli of supporting cells it measures approximately 75 nm. The functional implications of these findings are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216034
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  • 14
    Digitale Medien
    Digitale Medien
    Capacity of fertilized ova from mature and middle-aged rats to undergo preimplantation development in vitro (1983)
    Springer
    Cell & tissue research 229 (1983), S. 451-456 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Preimplantation development ; Rat ; Age
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ability of ova collected from mated middle-aged rats (9–10 months of age) to undergo preimplantation development in vitro was compared to that of younger controls (3–4 months of age). The majority of ova from young rats underwent at least one cleavage division for every 24 h of the 96 h culture period. Seventy-two percent reached the morula/blastocyst stage at the termination of the culture. Aged ova had a reduced capacity to undergo preimplantation development in vitro with the number of fragmented and/or degenerated ova increasing after each day in culture. At the end of the culture period, 81.6% of the ova had degenerated. It is concluded that middle-aged rats ovulate defective ova and that these defective ova account, in part, for the preimplantation losses that characterize middle-aged rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214986
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  • 15
    Digitale Medien
    Digitale Medien
    Depressive effect of LHRH on the numbers of “synaptic” ribbons and spherules in the pineal gland of diestrous rats (1983)
    Springer
    Cell & tissue research 229 (1983), S. 461-466 
    Details
    ISSN: 1432-0878
    Schlagwort(e): LHRH, effect of ; Pineal gland ; Synaptic ribbons ; Synaptic spherules ; Melatonin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Previous studies have shown that LHRH or LHRH-like substances are present in the pineal gland. In order to investigate whether exogenous LHRH may affect the pineal gland, in the present study the effects of a single dose of LHRH (1 μg, i.p.) on pineal “synaptic” ribbons and spherules as well as serum melatonin levels were examined in diestrous Wistar rats. One hour after the injection both ribbons and spherules exhibited a statistically significant decrease in number. Serum melatonin levels were not affected. It is concluded that humoral feedback mechanisms may exist between the hypothalamus and the pineal gland.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214988
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  • 16
    Digitale Medien
    Digitale Medien
    Improved demonstration of exocytotic profiles in glomus cells of rat carotid body after perfusion with glutaraldehyde fixative containing a high concentration of potassium (1983)
    Springer
    Cell & tissue research 229 (1983), S. 627-637 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Carotid body ; Rat ; Glomus cells ; Exocytosis ; High ; K fixation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Extensive secretion by exocytosis was demonstrated in the glomus (type I) cells of the adult rat after perfusion of carotid bodies with a potassium-rich (high K) glutaraldehyde fixative. Similar secretory profiles were very rare with a glutaraldehyde fixative containing a low concentration of potassium (low K). The increase in the incidence of exocytotic profiles in glomus cells with the high K fixative was highly significant, whereas no statistical difference could be observed in the incidence of coated pits with the different fixatives. Exocytotic profiles were characterized by the following features: (1) they predominated in non-synaptic regions, but were occasionally observed near synapses between two glomus cells; they were not observed near synapses between glomus cells and nerve terminals; (2) extruded electron-dense material associated with coating of the cell membrane was frequent; (3) different stages of dissolution of the extruded granule material was evident. The possible role of exocytosis as a mode of secretion in the glomus cells and the characteristics of the new high K-glutaraldehyde fixative are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00207702
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  • 17
    Digitale Medien
    Digitale Medien
    Ultrastructural changes rapidly induced by somatostatin may inhibit prolactin release in estrogen-primed rat adenohypophysis (1983)
    Springer
    Cell & tissue research 232 (1983), S. 21-34 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Prolactin ; Somatostatin ; Estrogen priming ; Adenohypophysis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Apart from the known hypothalamic controls, which have been well documented, a myriad of compounds both endogenous and exogenous have proved effective in influencing secretion of prolactin (PRL). Recent studies have shown that somatostatin (SRIF), when injected intra-atrially as a bolus, is able to inhibit PRL secretion in vivo. However, the inhibitory effect of SRIF occurs only in adenohypophyses previously primed with estradiol. This research was undertaken to examine the ultrastructural effects of that inhibition using male Sprague-Dawley rats primed for three weeks with subcutaneous implants of estradiol. Within 2 min of injection of SRIF (1 mg/kg), the adenohypophyses were removed and processed for electron microscopy. We found dramatic changes in the estradiol-primed mammotrophs, including 1) an apparent rearrangement of rough endoplasmic reticulum (RER) into concentric cisternae, and 2) the appearance of intracellular bodies closely associated with granules. These changes were not observed in non-estradiolprimed male rats injected with SRIF which is consistent with the fact that in the normal male rats, SRIF failed to inhibit PRL secretion. These findings suggest that SRIF causes reorganization of cellular organelles so that PRL granules are sequestered thereby inhibiting secretion of PRL.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222371
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  • 18
    Digitale Medien
    Digitale Medien
    Experimental study on the haematogenous origin of multinucleate osteoclasts in the rat (1983)
    Springer
    Cell & tissue research 233 (1983), S. 125-132 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Osteoclasts, origin of ; Macrophages ; Sex chromatin (Barr body) ; Ossification ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary When the resorption zones of the distal femoral and proximal tibial epiphyseal plates of rats are examined with the electron microscope, numerous macrophages can be seen surrounding degenerated chondrocytes. Macrophages are also found in the neighbourhood of the invading sinusoids and in close proximity to multinucleate osteoclasts. Cell fusion, however, could not be observed. Repeated transfusions of female leukocytes to isohistogeneic growing male rats caused an increase in the number of nuclei containing a Barr body in the osteoclasts of the males. The result suggests that leukocytes — of which only the monocytes come in question — are the source of multinucleate osteoclasts in endochondral ossification.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222237
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  • 19
    Digitale Medien
    Digitale Medien
    Retrograde axoplasmic transport of neurosecretory material (1983)
    Springer
    Cell & tissue research 233 (1983), S. 183-196 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retrograde transport ; Neurosecretory material ; Neurosecretory granules ; Hypothalamo-neurohypophyseal neurons ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The axonal transport of neurosecretory material was studied in neurosecretory axons of the supraoptico-posthypophyseal system after in-situ transection of the median eminence. Two hours, 8 h, and 18 h after the lesion, both vasopressin and oxytocin antibodies revealed progressive accumulations of immunoreactive material not only in the proximal but also in the distal stumps of the transected axons. The electronmicroscopic examination of these axonal portions revealed that such intense immunopositive labelings could be correlated, in both stumps, to a conspicuous accumulation of neurosecretory granules. It is concluded that, under normal physiological conditions, a significant amount of axoplasmic neurosecretory material is transported in retrograde direction and that such a retrograde transport mainly involves neurosecretory granules.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222242
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  • 20
    Digitale Medien
    Digitale Medien
    Preliminary observations of satellite cells in undamaged fibres of the rat soleus muscle assaulted by a snake-venom toxin (1983)
    Springer
    Cell & tissue research 230 (1983), S. 671-776 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Satellite cells ; Skeletal muscle ; Snake-venom toxin ; Muscle regeneration ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Satellite cells were studied in the undamaged part of the rat soleus muscle rendered partially necrotic by a subcutaneous injection of notexin, the myotoxic toxin purified from the venom of the Australian snake Notechis scutatus scutatus. Nuclei of satellite cells were twice as numerous as in the controls, with a decreasing gradient in the number of satellite cells with distance from the necrotic area. The cells were in an activated state with an increased cytoplasmic volume and prominent organelles. Occasionally, mitosis of some satellite cells was observed. Between the satellite cell and the muscle fibre, an unusually wide space was frequently seen, within which a “new” basal lamina was often visible. It is suggested that the role of the satellite cells of undamaged muscle fibres in the regeneration of necrotic muscle is worthy of more detailed investigation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216210
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  • 21
    Digitale Medien
    Digitale Medien
    Ontogenetic studies on the topographical heterogeneity of somatostatin-containing neurons in rat hypothalamus (1983)
    Springer
    Cell & tissue research 233 (1983), S. 347-354 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Development ; Somatostatin neuron ; Hypothalamus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ontogeny of the somatostatin-containing neuron system was investigated by light-microscopic immunohistochemistry. During development, immunoreactive somatostatin-containing neurons arise from three discrete regions of the neuroepithelium of the third ventricle and show a chronological difference. The neurons are first evident within the third ventricle floor on day 12.5 of gestation; they move thereafter to the arcuate nucleus. The second generation occurs in the dorsal region of the arcuate nucleus during days 17.5–19.5; these neurons migrate sequentially into the arcuate-ventromedial nuclear region. The third generation is recognized in the neuroepithelial cell layer of the rostral hypothalamus on day 17.5 of gestation; these cells move to the periventricular area. This latter generation is most prominent during days 3–6 after birth, and some of the cells are seen sporadically even up to day 20. The first two generations give rise to the somatostatin neuron system in the arcuate-ventromedial nuclear region, while the latter gives rise to that in the rostral periventricular region in the adult rat hypothalamus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238301
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  • 22
    Digitale Medien
    Digitale Medien
    Interrelations between neural elements and tanycytes during the perinatal period of the rat (1981)
    Springer
    Cell & tissue research 215 (1981), S. 635-641 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamo-hypophysial system ; Rat ; Supraependymal axons ; Ontogeny
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present study has utilized a correlative scanning-transmission electron microscopic technique to examine interrelations between neural elements and differentiated tanycytes and to identify supraependymal cells in the ventral region of the 3rd ventricle during the perinatal period in the rat. From the 18th day of fetal life monoaminergic and/or peptidergic axons penetrate into the ventricle between the tanycytes. After birth, they form an extensive network covering the surface of the infundibular recess. The axons possess morphological characteristics suggestive of neurohormone secretion. From the 20th day of prenatal life subependymal axons begin to “innervate” the tanycytes. Supraependymal cells differ in their shape and ultrastructure, but all of them bear resemblance to macrophages, as they contain numerous lysosomes and phagosome-like bodies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233537
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  • 23
    Digitale Medien
    Digitale Medien
    The effect of a liquid elemental diet on cell proliferation in the colon of rats (1981)
    Springer
    Cell & tissue research 216 (1981), S. 221-225 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Diet ; DNA synthesis ; Cell renewal ; Colon ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A liquid elemental diet (Vivonex) was given to rats for 6 days while control animals received a normal diet. At the end of the experiment each animal received one intraperitoneal injection of tritiated thvmidine at 8a.m. Animals from each group were killed hourly during the first 24h after the injection and the proliferative activity was studied by autoradiography of the mucosa of the colon using the labeled mitoses-wave method. The epithelial cell proliferation was significantly decreased in the colon of the Vivonex-fed animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234557
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  • 24
    Digitale Medien
    Digitale Medien
    Cerebellar intranuclear inclusions in chronically alcoholized rats (1981)
    Springer
    Cell & tissue research 216 (1981), S. 227-230 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cerebellum ; Nuclear inclusions ; Alcohol ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Nuclear rods and sheets are described in neurons from the cerebellar cortex of rats alcoholized through ingestion of a 20 % aqueous ethanol solution over a period of 90 and 180 days. An eventual relationship between these nuclear inclusions and alcoholization is advanced.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234558
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  • 25
    Digitale Medien
    Digitale Medien
    Growth of aortic vascular smooth muscle cells in lowered oxygen tension (1981)
    Springer
    Cell & tissue research 216 (1981), S. 591-602 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Vascular smooth muscle ; Tissue culture ; Hypoxia ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Primary cultures of vascular smooth muscle cells, isolated from rat aorta, were grown under normoxic (20% O2) and mildly hypoxic (5 % O2) conditions. Cells from both conditions were compared for growth characteristics, morphology, protein synthesis, lysosomal enzyme activity, and oxygen consumption. In no case was a consistently significant difference observed. These observations indicate that these cells can adapt or are adapted to mildly hypoxic conditions. Moreover, these results may indicate that the culture of vascular smooth muscle cells in mild hypoxia represents a closer approximation of in vivo growth conditions for these cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238654
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  • 26
    Digitale Medien
    Digitale Medien
    Role of estrogen and androgen in maintaining the preovulatory follicle (1981)
    Springer
    Cell & tissue research 216 (1981), S. 615-624 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Preovulatory follicle ; Ultrastructure ; Estrogen ; Androgen
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of Nitromifene citrate (CI 628), an antiestrogen, and Flutamide, an antiandrogen, on the ultrastructure and viability of the preovulatory follicle and granulosa cells were examined both in vivo and in vitro. In vivo administration of either antihormone induced degeneration within the granulosa cells. In some of the affected granulosa cells, the nuclear material was condensed while the cytoplasm and associated organelles were unaltered. In others, the density of the cytoplasm was reduced, the smooth endoplasmic reticulum was dilated but the nucleus remained unaltered. In vitro, either antihormone reduced granulosa-cell viability but the granulosa cells were twenty times more sensitive to CI 628 than to Flutamide. In addition, exposure to CI 628 induced nuclear condensation without affecting the cytoplasm, while Flutamide induced the deterioration of the cytoplasm without altering the nucleus. These observations suggest that: (1) both estrogen and androgens control the viability of the granulosa cells and thereby the follicle, (2) the action of estrogen and androgen is mediated through receptors within the granulosa cells since these antihormones prevent the nuclear uptake of their respective hormone, (3) the granulosa cells of preovulatory follicles appear to be more dependent on estrogen than on androgen, and (4) each steroid appears to have a specific role in maintaining the granulosa cell; estrogens control the integrity of the nucleus while androgens preserve the cytoplasmic organization of the granulosa cell.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238656
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  • 27
    Digitale Medien
    Digitale Medien
    Sex differences in adrenocortical structure and function (1983)
    Springer
    Cell & tissue research 232 (1983), S. 457-469 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Sex differences ; Adrenal cortex ; Rat ; Maturation ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This paper reports a stereological study of the cellular aspects of development of the adrenal cortex of male and female rats in the course of maturation. Rats of the Wistar strain were studied at weekly intervals from day 21 to day 77 of postnatal life. From day 42 homogenates of adrenals from female rats produced more corticosterone than homogenates from males of corresponding age. In the strain of rats studied sex differences in adrenal weight appeared at about day 49. From this day onward relative, and subsequently absolute adrenal weights were higher in females than in males. In the course of maturation the total volume of all adrenocortical zones gradually increased. From day 70 the zona glomerulosa and from day 49 the zona fasciculata were larger in female than in male rats, while no distinct sex difference was observed in the volume of the zona reticularis. The appearance of sex-related differences in the adrenal cortex depends mainly on changes in the zona fasciculata, the cells of which markedly increased in volume in female rats by comparison with males. The total number of all adrenocortical cells increased from ca 13 million on day 21 to ca 25 million on day 77 and at all intervals studied adrenal glands of male and female rats contained a similar number of parenchymal cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213800
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  • 28
    Digitale Medien
    Digitale Medien
    Catecholamine-storing cells in the adrenal medulla of the pre- and postnatal rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 155-170 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal medulla ; Development ; Acetylcholinesterase ; Small granule cells ; Ultramorphology ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The development of the rat adrenal medulla was studied at the ultrastructural level with particular emphasis placed on early discrimination of different catecholamine-storing cells. The first granule-containing cells, phaeochromoblasts, were seen at day 15 of gestation migrating into the anlage of the cortex. These cells were characterized by a few small granules (80–120 nm in diameter) and a high nuclear to cytoplasmic ratio. Presumably due to differentiation into chromaffin cells, they were no longer present after the eighth postnatal day. Maturation of phaeochromoblasts was indicated by an increase in number and size of their storage granules and a decrease in the nuclear to cytoplasmic ratio. Noradrenaline and adrenaline cell types were first clearly discernible at day 21 of gestation. Another cell type, a giant cell, was also recognized at this stage. In the adult animal, noradrenaline, two morphologically different types of adrenaline, and small granule-containing cells were observed. By applying acetylcholinesterase histochemistry, it was found that at day 17 of gestation a small population of granule-storing cells showed strong positive staining in the endoplasmic reticulum. In the adult animal this cell type was further characterized by small-storage granules. Other chromaffin cells began to show weak staining within the endoplasmic reticulum at day 19 of gestation. This staining appeared more frequently within adrenaline than noradrenaline cells. However, even in the adult animal many cells of both types were completely negative. It is concluded that acetylcholinesterase histochemistry is a useful method for early discrimination of small granule-containing cells in the developing rat adrenal medulla.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233834
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  • 29
    Digitale Medien
    Digitale Medien
    Terminal sprouting in rat sternocostalis muscle following partial denervation (1981)
    Springer
    Cell & tissue research 217 (1981), S. 189-198 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Sternocostalis muscle ; Partial denervation ; Motor neuron sprouting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The sternocostalis muscle of the rat was examined at one to five days after partial denervation and levels of terminal sprouting were assessed. The removal of one intercostal nerve caused localised degeneration which did not extend more than a few muscle fibres deep into the field of distribution of the adjacent nerve. Terminal sprouting was clearly seen at 24 h after operation and did not appear to develop further up to five days. There was no difference in the sprouting responses to section of either intercostal nerve 2, 4 or 5. There was, however, a decrease in the response with increasing distance from the cut nerve. No sprouting response was observed in the contralateral muscle. Comparison of sprouting levels of B and C type end plates revealed a greater percentage of C type end plates with sprouts. However, the response of B type end plates, considered in relation to the levels of spontaneous sprouting, was greater than that of C type end plates.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233837
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  • 30
    Digitale Medien
    Digitale Medien
    Effects of tunicamycin on the hypothalamo-neurohypophysial system of the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 199-210 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamus ; Neurohypophysis ; Neurophysin ; Secretion ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Intracisternal injections of tunicamycin, an inhibitor of glycosylation, decreased the incorporation of [35S]cysteine into the neurophysins in the rat neurohypophysis. Histochemical and immunocytochemical studies showed that there was no concomitant decrease in the amount of secretory product in the perikarya of the hypothalamo-neurohypophysial neurones. Indeed there was an increase, although this was not associated with neurosecretory granules as judged electron-microscopically. Tunicamycin led to the formation of socalled “colloid droplets” which were immunopositive and of which the ultrastructural correlates appeared to be product-filled dilatations of the rough endoplasmic reticulum. The observations are interpreted to suggest that glycosylation plays a rôle in the packaging of secretory material in the hypothalamo-neurohypophysial system.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233838
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  • 31
    Digitale Medien
    Digitale Medien
    A retinal projection to the lateral hypothalamus in the rat (1981)
    Springer
    Cell & tissue research 214 (1981), S. 257-269 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Retinal projection ; Lateral hypothalamus ; Dendrites in optic tract ; Axodendritic synapses ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary This study presents evidence for a retinal projection to neurons in the lateral hypothalamic area (LHA) of the albino rat. In Golgi-Kopsch material dendrites from LHA-neurons are observed to extend through the supraoptic commissures into the optic tract. The presence of dendrites in the optic tract is confirmed by electron microscopy. Numerous axon terminals are observed forming asymmetric synaptic contacts with these dendritic profiles. Following bilateral enucleation, many of the preterminal axons and terminals in synaptic contact with dendrites in the optic tract demonstrate dark degeneration. After intraocular injection of horseradish peroxidase, there is marked labeling of preterminal axons and terminals in the optic tract. These observations indicate that LHA neurons receive a direct retinal projection from terminals making synaptic contact with dendrites of LHA-neurons extending into the optic tract.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00249210
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  • 32
    Digitale Medien
    Digitale Medien
    The temporo-spatial course of degeneration after cutting cortico-cortical connections in adult rats (1981)
    Springer
    Cell & tissue research 214 (1981), S. 303-321 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cortico-cortical connections ; Degeneration ; Time course ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Adult albino rats received callosotomies or lesions in the paracingular cortex. Between 12 h and 3 months after injury the structure and topography of the degeneration products were studied by light- and electron-microscopy. The degeneration process was quantified by television-image analysis applied to sections prepared according to a new technique that stains reliably degenerating terminals and lysosomes (Gallyas et al. 1980). All types of cortico-cortical connections show a multiphasic degeneration process: During a precursor stage a small number of dense bodies and mitochondrial granules are stained. These and the few early degenerating axon terminals are much more diffusely distributed than the large number of terminals that degenerate during the following period. The terminal degeneration shows a biphasic time course. One maximum appears at 2–7 days post operation, which corresponds to the well known direct consequence of axotomy. The second peak at 10–20 days post operation could be caused by transneuronal reorganization of the cortical connectivity. Terminal degeneration always begins along the borders between cortical regions and areas, but it may change its laminar and columnar distribution pattern during the second phase. The degeneration products that are phagocytosed by astrocytes seem to be removed by intracellular transport to their perivascular endfeet. The degeneration process ends with fiber degeneration which, especially in laminae I and VI, may form a separate peak after 20 days or more.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00249214
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  • 33
    Digitale Medien
    Digitale Medien
    Effects of pimozide on the ultrastructure of the pars intermedia in the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 397-403 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland ; Rat ; MSH-cells ; Pimozide ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effects of pimozide, a dopamine receptor-blocking agent, were studied in the pars intermedia of the rat. The animals received 100 μg/100 g pimozide daily for 2, 5, 10, 15, and 20 days. Pimozide induces ultrastructural changes after 5 days of treatment. About 50% of the MSH-cells display characteristics of stimulation. Their cytoplasm is partially or totally depleted of secretory granules. The rough endoplasmic reticulum displays a network of interconnecting cisternae and ribbon-like structures. The well-developed Golgi complexes exhibit numerous dilatations of their cisternae, which contain electron-dense material. The nerve endings are not altered. Twenty days after treatment, the above-described changes have not decreased in magnitude. The present findings suggest that pimozide stimulates the mechanism of synthesis and release in some MSH-cells, most probably the elements underlying an inhibitory dopaminergic control.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233589
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  • 34
    Digitale Medien
    Digitale Medien
    Somatostatin-immunoreactive fiber projections into the brain stem and the spinal cord of the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 531-552 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Somatostatin fiber projections ; Brain stem ; Spinal cord ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary By use of the PAP-immunohistochemical staining technique with serial sections, somatostatin-immunoreactive fiber projections into the brain stem and the spinal cord are described. These projections originate in the periventricular somatostatin-immunoreactive perikarya of the hypothalamus and form three main pathways: (1) along the stria medullaris thalami and the fasciculus retroflexus into the interpeduncular nucleus; (2) along the medial forebrain bundle into the mammillary body; and (3) via the periventricular gray and the bundle of Schütz into the midbrain tegmentum. Densely arranged immunoreactive fibers and/or basket-like fiber terminals are observed within the following afferent systems: somatic afferent systems (nucleus spinalis nervi trigemini, substantia gelatinosa dorsalis of the entire spinal cord), and visceral afferent systems (nucleus solitarius, regio intermediolateralis and substantia gelatinosa of the sacral spinal cord). These projections form terminals around the perikarya of the second afferent neuron. Perikarya of the third afferent neuron are influenced by somatostatin-immunoreactive projections into the auditory system (nucleus dorsalis lemnisci lateralis, nucleus corporis trapezoidei). Furthermore, a somatostatin-immunoreactive fiber projection is found in the ventral part of the medial accessory olivary nucleus, in nuclei of the limbic system (nucleus habenularis medialis, nuclei supramamillaris and mamillaris lateralis) and in the formatio reticularis (nucleus Darkschewitsch, nuclei tegmenti lateralis and centralis, nucleus parabrachialis lateralis, as well as individual perikarya of the reticular formation). Targets of these projections are interneurons within interlocking neuronal chains.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219362
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  • 35
    Digitale Medien
    Digitale Medien
    Synaptic input to the axon hillock and initial segment of inhibitory interneurons in the cerebellar cortex of the rat (1981)
    Springer
    Cell & tissue research 217 (1981), S. 553-562 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Axon hillock ; Interneurons ; Cerebellar cortex ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The axon hillock (AH) and initial segment (IS) of 10 Golgi neurons and 6 basket cells in the cerebellar cortex of the rat were investigated by electron microscopy using serial sections. An average of 10.4 and 11.3 synaptic terminals were observed to establish synaptic contact with the axon hillock region of Golgi and basket cells, respectively. Most of these terminals were identified as the varicosities of the ascending parallel fibers. It is suggested that the focal innervation of AH regions represents an excitatory input pattern which is basically different from the randomly distributed, huge, parallel-fiber input onto the dendritic trees of Golgi and basket cells. In contrast to Golgi and basket neurons, no accumulation of parallel-fiber synapses was observed around the AH of stellate cells. The IS proper of the three neuronal types were devoid of true axo-axonal synapses.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219363
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  • 36
    Digitale Medien
    Digitale Medien
    Ultrastructural observations on rapid formation of neuro-muscular junctions in vitro (1981)
    Springer
    Cell & tissue research 217 (1981), S. 647-659 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cell culture ; Neuro-muscular junctions ; Short-term preparations ; Mouse ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The development of neuro-muscular junctions (mouse, rat) from the time of first contact between neurons and myotubes in culture and the changes which lead to the formation of functional synaptic contacts have been investigated using light microscopy and ultrastructural techniques. An extensive basal lamina was present when the neuronal cell population was added to the developing myotubes in culture. The nerve cells were initially strongly attracted to each other and nerve cell aggregates formed rapidly. It was only when nerve fibres began to grow out of these aggregates to contact developing myotubes that changes within the cytoplasm of the two adjacent cells were observed. These developments included accumulations of filaments, membrane densities, mitochondria and large clear vesicles within both cells in the region of contact. In addition, collections of glycogen granules and an extensive membrane reticular complex were found within myotubes, and an extensive granular material filled many of the nerve processes. The basal lamina within the intercellular space appeared more electron-dense than elsewhere and was traversed by strands linking the two cell membranes. These features all appeared to be stages in the initial formation of neuro-muscular junctions. It was only after these events had occurred that presynaptic vesicles gradually appeared within the future nerve terminal. The results of this paper therefore support the view that synaptic transmission at developing mammalian neuromuscular junctions is not necessarily dependent on the presence of presynaptic vesicles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219371
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  • 37
    Digitale Medien
    Digitale Medien
    The effects of short-term fluoride ingestion on bone formation and resorption in the rat femur (1981)
    Springer
    Cell & tissue research 221 (1981), S. 421-430 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Fluoride ; Bone ; Mineralization ; Resorption ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The femurs from rats given 120 ppm fluoride in their drinking water for 4 weeks were examined with histological, histochemical, and radiographic methods. Blood removed from the rats prior to sacrifice was analyzed for calcium, phosphorus, and alkaline phosphatase. Results of this study indicated that the ingestion of fluoride produced wide osteoid seams on the periosteal surface of the femoral diaphysis within 4 weeks. The increase in osteoid appeared to be due to an increase in the number of osteoid-producing cells (osteoblasts) along with a subsequent delay in the mineralization of this tissue. The metabolic activity of osteoblasts did not appear to be affected since the intracellular production of acid and alkaline phosphatase was not inhibited. However, due to the high concentration of fluoride ingested, abnormal collagen deposition and a change in bone mineral may have combined to cause a delay in osteoid mineralization. Mineralization was also delayed in the distal femoral epiphyseal plate resulting in an increase in the number of hypertrophied cells. Resorption of metaphyseal trabecular bone, presumably formed prior to fluoride administration, was increased causing a reduction in the amount of trabeculae extending into the shaft of the femur. Concurrent with these changes in bone, the serum levels of calcium, phosphorus, and alkaline phosphatase remained within normal ranges.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216745
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  • 38
    Digitale Medien
    Digitale Medien
    Ultrastructure of elastic cartilage in the rat external ear (1981)
    Springer
    Cell & tissue research 218 (1981), S. 149-160 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Elastic cartilage ; External ear ; Rat ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The structure of elastic cartilage in the external ear of the rat was investigated by transmission and scanning electron microscopy. The narrow subperichondrial, boundary zone contains predominantly ovoid cells rich in cell organelles: mitochondria, Golgi complex, granular endoplasmic reticulum and small (40–100 nm) vesicles. Scarce glycogen granules and bundles of 6–7 nm cytoplasmic filaments are also present. Deeper in the boundary zone, one or more cytoplasmic lipid droplets appear and cytofilaments become more abundant. Fully differentiated chondrocytes in the central zone of the cartilage plate resemble white adipose cells. They are globular and contain a single, large cytoplasmic lipid droplet. The cytoplasm is reduced to a thin peripheral rim; it contains a flattened nucleus, few cytoplasmic organelles and abundant, densely packed, cytoplasmic filaments. The intercellular matrix is very sparse. The pericellular ring consists of collagen fibrils about 20 nm in diameter and a proteoglycan cartilage matrix in the form of a “stellate reticulum”. The complex of these two structures appears in the scanning electron micrographs as a network of randomly oriented, ca 100 nm thick fibrils. Spaces between pericellular rings of matrix also contain thick elastic fibers or plates, apparently devoid of microfibrils. In scanning electron micrographs elastic fibers could be detected only in a few areas, in which they were not obscured by other constituents of the matrix. Immature forms of elastic fibers, oxytalan (pre-elastic) and elaunin fibers, were found in the perichondrial and boundary zones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210101
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  • 39
    Digitale Medien
    Digitale Medien
    Immunocytochemical localization of TRH and autoradiographic determination of 3H-TRH-binding sites in the arcuate nucleus-median eminence of the rat (1983)
    Springer
    Cell & tissue research 228 (1983), S. 475-487 
    Details
    ISSN: 1432-0878
    Schlagwort(e): TRH ; Immunocytochemistry ; Autoradiography ; Arcuate nucleus ; Median eminence ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunocytochemical and autoradiographic localization of thyrotropin-releasing hormone (TRH)-and 3H-TRH-binding sites was studied in the arcuate nucleus-median eminence region of the rat. TRH-like immunoreactivity was found in dense granular vesicles (90–140 nm in diameter) in TRH-like immunoreactive nerve fibers and terminals. In the median eminence, the immunoreactive terminals were observed to be in direct contact with the perivascular basal lamina of the portal vessel and to form synaptoid contacts with tanycytes. In the arcuate nucleus, the immunoreactive terminals were often found to form axosomatic and axo-axonic, and/or axo-dendritic synapses. The uptake of tritiated TRH into the nerve fibers and terminals of the median eminence was also observed by autoradiography and the distribution and localization of silver grains in them were analyzed quantitatively by circle analysis. Thirty minutes after intraventricular infusion of 3H-TRH, radioactive labeling occurred in type-2 and 3-nerve fibers and terminals containing dense granular vesicles in the median eminence. It is therefore suggested that the neurons labeled after 3H-TRH infusion possess certain functions as physiological recognition sites or receptors for TRH.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00211469
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  • 40
    Digitale Medien
    Digitale Medien
    The meningeal compartments of the median eminence and the cortex (1983)
    Springer
    Cell & tissue research 228 (1983), S. 597-640 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Meningeal compartments ; Median eminence ; Cortex ; CSF-and hemal milieu ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The intervascular segments of the leptomeninges of the rat were studied by the use of horseradish peroxidase (HRP) in short-term experiments. HRP was injected (i) intravenously, (ii) into the lateral ventricle, (iii) into the cortex, and (iv) into the meninges. The composition of the meninges covering the median eminence (ME) was analyzed in comparison to the results obtained with the parietal cortex. The meninges covering the cortex show the following pattern of layers and compartments: The intercellular compartment comprises the intercellular clefts of the neuropil, the subpial space, and the intercellular clefts of the leptomeninges. The pial space establishes a second compartment. The third compartment is the arachnoid space. The intercellular clefts of the dura form the fourth compartment. At the border of the ME, the neurothelium and the outer arachnoid layer are rolled up to form a tissue frame around a hollow pit that is covered by a diaphragm consisting of meningeal cells; the latter separate the hemal milieu of the ME from that of the dura. The hemal and the cerebrospinal fluid (CSF) milieus may communicate to a limited extent only within the subpial space adjacent to the ME. The CSF-containing compartments of the pial and arachnoid spaces terminate at the brain-facing insertion of the tissue frame. According to the present results, an anatomical basis for a short-loop feedback from and to the neurohemal region of the ME via the CSF does not exist.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00211479
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  • 41
    Digitale Medien
    Digitale Medien
    Vacuoles in macrophages and reticular cells of regional lymph nodes of the rat after injection of large doses of steroids (1983)
    Springer
    Cell & tissue research 230 (1983), S. 57-65 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Lymph node ; Steroid ; Reticular cell ; Macrophage
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of macrophages and reticular cells of regional lymph nodes of the rat after administration of large doses of cortisone acetate, estrone, progesterone, and cholesterol in aqueous suspensions was investigated. A large number of vacuoles, most of which were surrounded by unit membrane, and lipid droplets not surrounded by unit membrane were observed in the cytoplasm of both macrophages and reticular cells. They were not seen in these cells of control animals and in experimental animals that had received smaller doses of these steroid hormones. After cholesterol injection, many lipid droplets were observed in the cytoplasm of macrophages. These observations suggest that steroids injected in suspension accumulate in macrophages and reticular cells of the regional lymph nodes. Electron-dense material was often present in vacuoles of macrophages but not in those of reticular cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216027
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  • 42
    Digitale Medien
    Digitale Medien
    Influence of melatonin on the process of protein and/or peptide secretion in the pineal gland of the rat and hamster (1983)
    Springer
    Cell & tissue research 231 (1983), S. 73-82 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal organ ; Melatonin ; Pineal protein secretion ; Rat ; Hamster
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The hypothesis that melatonin (aMT) is implicated in the regulation of the secretory process involved in the synthesis and release of protein/peptide “hormones” of the pineal organ has been tested in the present study by the use of an in vitro system in two mammalian species. In these species the secretory process studied is characterized by either large (hamster) or very small (rat) numbers of granular vesicles. In both species, aMT clearly participates in the regulation of the process of protein/peptide secretion. However, the effect of aMT varies with the presence of noradrenaline (NA) in the medium and is not identical in both species. Melatonin, in the absence of NA, induces the formation of granular vesicles by the Golgi apparatus in pinealocytes of the rat but not in those of the hamster, while in the presence of NA, aMT provokes a decrease in the number of these vesicles in both species. The present experiments show (i) that the pineal is one of the target organs for aMT, and (ii) that aMT is implicated in the control of protein/ peptide secretion in the pineal organ.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00215775
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  • 43
    Digitale Medien
    Digitale Medien
    Ultrastructure of the endometrial blood vessels during implantation of the rat blastocyst (1983)
    Springer
    Cell & tissue research 229 (1983), S. 269-280 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Uterus ; Implantation ; Blood vessels ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructure of the blood vessels of the endometrium was analysed during implantation of the blastocyst in rats, at the time of appearance of the Pontamine Blue Reaction. Vessels from implantation sites and from interimplantation sites were compared. In vessels from implantation sites the endothelial cells showed fenestrations covered by diaphragms. In addition, small interruptions (gaps) between the endothelial cells were observed. These features were present in vessels larger than 5 μm in diameter and more than 100 μm away from the uterine epithelium, both in the mesometrial and antimesometrial wall of the endometrium. Vessels from interimplantation sites displayed neither fenestrations nor interruptions. The endothelial cells of the implantation sites displayed morphological signs of metabolic activation. These consisted of increased numbers of polyribosomes, well developed Golgi complexes and prominent nucleoli. The fenestrations and gaps in the vessel wall were interpreted as constituting the morphological basis for the increase in vascular permeability and the consequent edema which characterize the Pontamine Blue Reaction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00214975
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  • 44
    Digitale Medien
    Digitale Medien
    Complexes of annulate lamellae and nemaline bodies in soleplate nuclei in skeletal muscle fibers of the normal rat (1983)
    Springer
    Cell & tissue research 231 (1983), S. 337-346 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Annulate lamellae ; Neuromuscular junction ; Muscles Cell nucleus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Pseudointranuclear inclusions resulting from invaginations of the nuclear envelope, characteristic of myopathic muscles, were found in the soleplate nuclei of normal soleus muscles of rats. Such inclusions had annulate lamellae (AL), nemaline or rod bodies, lamellar structures, a concentric system of membranes, as well as tightly packed sarcoplasmic organelles. An accumulative origin of such included structures was suggested. The AL were sometimes connected directly to the outer membrane enclosing the inclusions, dilated into cisterns and positioned perpendicularly against the nuclear surface. AL, some of which were welldeveloped, were observed in the same loci as above during the course of denervation atrophy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222185
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  • 45
    Digitale Medien
    Digitale Medien
    Evidence for protein absorption from the lumen of the seminiferous tubule and rete of the rat testis (1983)
    Springer
    Cell & tissue research 230 (1983), S. 367-375 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Testis ; Protein ; Endocytosis ; Microperfusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary As luminal fluid moves from the seminiferous tubule and enters the rete testis, its protein concentration declines from approximately 6 mg/ml to 1 mg/ml. It was therefore suggested that protein is either 1) utilized by the spermatozoa, 2) transported across the epithelium of the terminal segment of the seminiferous tubule, the tubuli recti or rete testis, or 3) absorbed and degraded by the epithelium. Horseradish peroxidase (HRP), a protein marker, was microperfused into single seminiferous tubules or perfused directly into the rete. After fixation, the HRP was localized histochemically and the tissue observed under the light- and electron microscope. HRP was taken up via pinocytotic vesicles into the cytoplasm of the Sertoli cells and germ cells but did not permeate extracellularly beyond the tight junctions. Similar results were obtained in the cells lining the terminal segment and the tubuli recti. The rete epithelium showed uptake of HRP into coated and noncoated vesicles, while some cells additionally revealed diffuse cytoplasmic distribution of HRP. The terminal segment, tubuli recti, and rete testis may be important routes by which proteins may leave the testicular fluid either to be degraded or to enter the blood.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213810
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  • 46
    Digitale Medien
    Digitale Medien
    Correlative ontogenetic development of catecholamine- and LHRH-containing nerve endings in the median eminence of the rat (1981)
    Springer
    Cell & tissue research 216 (1981), S. 31-38 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Median eminence ; Rat ; Ontogeny ; LHRH ; Catecholamines
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ontogenetic development of catecholamine (CA)-and LHRH-containing nerve endings in the median eminence of the rat was investigated by combining fluorescence histochemistry and immunohistochemistry in the same tissue section. LHRH-terminals appeared earlier than CA-terminals and were already detectable in the lateral part of the external layer of the central ME on the first day after birth. CA-nerve endings were first seen in a corresponding region of the ME on the seventh postnatal day. At this stage both types of terminals showed the earliest manifestation of a correlative pattern of their distribution. Subsequently the development of both types of nerve endings proceeded rapidly, and at 14 days their distribution pattern corresponded to that in adult animals. The authors conclude that at this stage the CA-neurons play a constant and significant role in the release of LHRH into the portal capillaries. The correlation between both types of nerve endings and the ontogenetic development of the capillary plexuses of the hypophysial portal system is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234542
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  • 47
    Digitale Medien
    Digitale Medien
    Changes in oxytocin content in the magnocellular neurons of the rat hypothalamus following water deprivation or estrogen treatment (1981)
    Springer
    Cell & tissue research 216 (1981), S. 47-55 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Oxytocin ; Paraventricular nucleus ; Supraoptic nucleus ; Anterior commissural nucleus ; Immunohistology ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The effect of water deprivation or estrogen treatment on the oxytocin content of rat hypothalamic cells was examined using a quantitative immunohistological technique. Oxytocin-containing cells were visualized using the immunoperoxidase technique of Sternberger and a primary antiserum directed against oxytocin. The optical density of the darkest 3.2 μm diameter spot in the cytoplasm of a cell was used as a measure of the oxytocin content of that cell. Water deprivation produced a significant decrease in anti-oxytocin staining in the anterior commissural nucleus of males and females. There was a similar decrease in the paraventricular nucleus of males, but not in the paraventricular nucleus of females or the supraoptic nucleus of either males or females. Estrogen treatment of ovariectomized female rats produced a fall in anti-oxytocin staining in the anterior commissural, but not paraventricular or supraoptic nuclei.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234544
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  • 48
    Digitale Medien
    Digitale Medien
    Demonstration of a class of porphyrin-containing cells in the pars intermedia of the rat hypophysis (1983)
    Springer
    Cell & tissue research 232 (1983), S. 257-264 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pars intermedia ; Rat ; Porphyrins ; Microspectrofluorometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cells emitting orange-red autofluorescence have been found in the pars intermedia of aging rats. The fluorescence maximum of the emission is localized in an area of the spectrum where the most intense band maxima of porphyrins are located. The fluorescence fades when the excitation wavelength is about 400 nm, which is specific (Soret band) for the absorption spectra of porphyrins. The fluorescence is emitted by coarse inclusions in the cytoplasm of a few cells. These inclusions are also stainable with paraldehyde-fuchsin and exibit a high endogenous peroxidase activity. The inclusions observed have morphologic features similar to those of porphyrin-containing astrocytes from the periventricular area of the hypothalamus. The inclusion-bearing cells of the pars intermedia also contain debris that might be due to the phagocytic activity of these cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213785
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  • 49
    Digitale Medien
    Digitale Medien
    Ultrastructural study of electrophysiologically identified neurones in the paraventricular nucleus of the rat (1981)
    Springer
    Cell & tissue research 216 (1981), S. 503-512 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Paraventricular neurones ; Alcian-blue labelling ; Ultrastructure ; Electrophysiology ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural characterization of electrophysiologically identified neurones of the rat paraventricular hypothalamic nucleus was performed with extracellular labelling technique. The extracellularly recorded neurones are labelled with an electrophoretic deposit of alcian blue contained in the recording micropipette. The neurone thus labelled takes on a dark and shrunken appearance which enables its detection among neighbouring cells without, however, concealing its main morphological characteristics. 1) Spontaneously firing neurones, invaded by an antidromic action potential elicited by electrical stimulation of the neurohypophysis, were identified as magnocellular cells containing dense-cored vesicles of 200–250 nm in diameter. Dense-cored vesicles were not found in the antidromically activated neurones devoid of spontaneous activity. 2) Trans-synaptically activated neurones in the PVN or in its dorso-lateral edge were small cells devoid of dense secretory vesicles. 3) PV neurones in which neurohypophysial stimulation evoked no response, contained small, dense vesicles (100 nm in diameter) comparable with those found in parvocellular peptidergic neurones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238647
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  • 50
    Digitale Medien
    Digitale Medien
    Extracellular matrix vesicles in rat bone after parathyroidectomy (1983)
    Springer
    Cell & tissue research 228 (1983), S. 451-457 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Bone matrix vesicles ; Parathyroid hormone ; Mineralization ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The enzymatic activity of bone matrix vesicles from parathyroidectomized rats was determined and compared to the activity of vesicles from sham operated and normal animals. The vesicles were isolated from the alveolar bone by collagenase digestion and differential centrifugation and further purified on a discontinuous sucrose density gradient. The amount of extractable protein and the activity of alkaline phosphatase, acid phosphatase, and ATPase in the vesicle fractions thus obtained did not differ significantly from the values characteristic of preparations from control rats. It may therefore be suggested that parathyroid hormone depletion and the associated hypocalcemia have no significant effect on the occurrence and phosphatase activity of bone matrix vesicles.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00211467
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  • 51
    Digitale Medien
    Digitale Medien
    Pituitary folliculo-stellate cells immunostained with S-100 protein antiserum in postnatal, castrated and thyroidectomized rats (1983)
    Springer
    Cell & tissue research 231 (1983), S. 235-249 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary gland ; S-100 protein ; Castration ; Thyroidectomy ; Postnatal development ; Immunocytochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Pituitary folliculo-stellate cells and associated cells were studied immunohistochemically throughout the life of male and female rats. The marginal layer cells of the pars distalis and intermedia as well as the folliculo-stellate cells were immunostained with anti-S 100 protein serum. The immunostained folliculo-stellate cells in one section were identified as themselves by their ultrastructural properties on the adjacent section. Corticotrophs, thyrotrophs and prolactin cells, characterized by the stellate shape, were not immunostained with anti-S 100 protein serum. Reactivity for S-100 protein appeared on postnatal Day 6 in the marginal layer cells of the pars intermedia, and appeared on Day 10 in those cells of the pars distalis. No immunostained folliculostellate cells appeared before Day 6, but a few of them appeared on Day 10. Thereafter they increased in number, having more intense immunostaining with advancing age. In castrated rats, the immunostained folliculo-stellate cells appeared quite numerously, with branched cytoplasmic processes surrounding the gonadotrophs. In the thyroidectomized rats, however, folliculo-stellate cells lacked ramified cytoplasmic processes, and their topographic affinity for thyrotrophs was negligible.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222177
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  • 52
    Digitale Medien
    Digitale Medien
    Immunohistochemical identification of neurons containing corticotropin-releasing factor in the rat hypothalamus (1983)
    Springer
    Cell & tissue research 230 (1983), S. 239-246 
    Details
    ISSN: 1432-0878
    Schlagwort(e): CRF neurons ; Hypothalamus ; Immunohistochemistry ; PAP ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A specific rabbit anti-CRF serum and the immunoperoxidase technique were used to show that CRF-containing neurons are mainly distributed in the paraventricular and supraoptic nuclei of the rat hypothalamus. In addition, immunoreactive neurons are scattered in other hypothalamic regions. These neurons are 20–30 μm in diameter. From the present and previous investigations it may be concluded that the hypothalamic magnocellular nuclei, i.e., paraventricular and supraoptic, and other hypothalamic accessory nuclei, are the producing sites not only for vasopressin and oxytocin, but also for corticotropin-releasing factor.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213802
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  • 53
    Digitale Medien
    Digitale Medien
    Differences in the distributional pattern of CRF-, oxytocin-, and vasopressin-immunoreactive nerve fibers in the median eminence of the rat (1983)
    Springer
    Cell & tissue research 230 (1983), S. 247-258 
    Details
    ISSN: 1432-0878
    Schlagwort(e): CRF ; Oxytocin ; Vasopressin ; Immunohistochemistry ; Median eminence ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Conspicuous differences in the distributional pattern of nerve fibers containing corticotropin-releasing factor (CRF) or posterior lobe hormones, respectively, were shown in the median eminence of the adult male rat by means of immunoperoxidase histochemistry, with the use of anti-CRF, anti-oxytocin, and anti-vasopressin sera. In the rostral and central divisions of the median eminence, a high concentration of CRF-immunoreactive nerve fibers was found in the median portion of the external layer; these fibers terminated on the capillary loops of the hypophysial portal system. In the caudal division of the median eminence, the CRF-immunoreactive nerve fibers were located in the median to paramedian portions of the external layer. Numerous oxytocin- and vasopressin-immunoreactive nerve fibers were observed evenly distributed throughout the internal layer of the median eminence. In the external layer, a small number of the oxytocin- and vasopressin-containing nerve fibers was found around the capillary loops, particularly in the median to paramedian portions. The distributional patterns of the CRF and the posterior lobe hormones in the hypothalamo-hypophysial system and their functional interrelationship are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213803
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  • 54
    Digitale Medien
    Digitale Medien
    6-OHDA-induced ectopia of external granule cells in the subarachnoid space covering the cerebellum (1983)
    Springer
    Cell & tissue research 230 (1983), S. 309-336 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neural ectopia ; Cerebellum ; Granule cells ; Development ; 6-Hydroxydopamine ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present report describes the genesis, development and topographical distribution of ectopic cells of the external granular layer in the subarachnoid space covering the rat cerebellum. Following one intracisternal injection to newborn rats of 100 μg 6-hydroxydopamine (6-OHDA), the meningeal cells degenerate and are removed by phagocytosis within 24 h post injection (p.i.), leaving the cerebellar cortex without a pia-arachnoid cover. Defects appear in the basal lamina investing the cerebellar cortex 3 to 5 days p.i., and both external granule cells and ‘sprouts’ from Bergmann-glia endfeet grow into the subarachnoid space. The latter form large, flat glial lamellae and cover extensive areas of the denuded cerebellar surface, although they do not form a glial scar over the exposed neuropil of the cerebellar cortex. The numbers of ectopic external granule cells increase within the subarachnoid space both by proliferation and a continuous efflux of cells from the cerebellar cortex. They migrate, aggregate, and ultimately develop into granule, stellate and basket cells, the morphology of which is indistinguishable from their counterparts in situ; they make specific afferent and efferent connections, both among themselves and with the underlying cerebellar cortex and brainstem. The distribution of ectopic external granule cells and their derivatives is restricted to the anterior vermal fissures and the vermal-hemispheric junctions. The present results indicate that external granule cells and their derivatives are capable of both differentiating normally and surviving in the subarachnoid space if they become associated with glial cells and establish synaptic connections.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00213807
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  • 55
    Digitale Medien
    Digitale Medien
    Nerve fibers in the gut and pancreas of the rat displaying neuropeptide-Y immunoreactivity (1983)
    Springer
    Cell & tissue research 230 (1983), S. 487-493 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Neuropeptides ; Autonomic nervous system ; Gut innervation ; Neuropeptide Y ; Pancreatic polypeptide ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunoreactive neuropeptide Y (NPY) was demonstrated in neuronal elements in the gut and pancreas of the rat. Immunoreactive endocrine cells could not be detected. The occurrence of NPY containing nerve-cell bodies in the submucosal and myenteric ganglia indicates an intrinsic origin of the NPY fibers. However, an additional extrinsic supply of NPY fibers is suggested by the finding that abdominal sympathectomy caused the disappearance of some NPY fibers, notably those around blood vessels. The distribution of NPY fibers in all layers of the gut wall suggests multiple functions of NPY, including a role in the regulation of intramural neuronal activities, smooth muscle tone, and local blood flow.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216194
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  • 56
    Digitale Medien
    Digitale Medien
    Permeability of the blood-brain barrier in the median eminence during the perinatal period in rats (1983)
    Springer
    Cell & tissue research 230 (1983), S. 649-660 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamo-hypophysial system ; Capillaries ; Permeability ; Ontogenesis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary An electron microscopic study has been carried out in order to examine the permeability of the blood-brain barrier in the median eminence of perinatal rats. After several minutes, intravascularly injected electron-dense tracers (lanthanum nitrate; horseradish peroxidase, 40000 MW MW: molecular weight , ferritin, 500000 MW) pass the capillary wall, the perivascular space, and become incorporated into neurosecretory axons and basal processes of tanycytes both in fetuses and young rats. In the case of immature capillaries, the materials diffuse freely through the endothelial cells, and to a lesser extent are transferred via occasional plasmalemmal vesicles and fenestrae. As the maturation of capillaries proceeds, their permeability via plasmalemmal vesicles and fenestrae increases considerably due to a gradual rise of the number of these structures. The plasmalemmata of the differentiated endothelial cells become impermeable to all of the tracers. Only ionic lanthanum appears to penetrate through transendothelial channels and intercellular junctions between adjacent endothelial cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00216208
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  • 57
    Digitale Medien
    Digitale Medien
    Morphometric investigations into the mechanism of the compensatory hypertrophy of the rat adrenal zona fasciculata after unilateral adrenalectomy (1983)
    Springer
    Cell & tissue research 234 (1983), S. 573-578 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenalectomy ; Hypophysectomy ; Compensatory adrenal growth ; Rat ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Compensatory hypertrophy of the remaining gland in unilaterally adrenalectomized rats was investigated by morphometric techniques. It was observed that compensatory adrenal growth occurred in both dexamethasone-treated and hypophysectomized rats, receiving maintenance doses of ACTH. However, it was only half that found in intact animals. These results support the view that activation of the hypothalamo-hypophyseal axis is not the unique mechanism underlying adrenal compensatory hypertrophy in the rat.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00218652
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  • 58
    Digitale Medien
    Digitale Medien
    Distribution and morphological characteristics of the pit cells in the liver of the rat (1983)
    Springer
    Cell & tissue research 233 (1983), S. 485-505 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Liver ; Pit cell ; Cytoplasmic granules ; Vesicles ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Pit cells, on which almost no further contributions have been presented since the first report by Wisse et al. (1976), are described in detail in the rat liver. These cells show several characteristic features: 1) “rod-cored vesicles”, a new type of vesicular inclusion observed first in our study; 2) electron-dense granules, which we consider to arise from multivesicular bodies by the accumulation of dense material; and 3) well-developed pseudopodia. Although these features clearly differentiate pit cells from conventional lymphocytes, these two cell types display similarities (i) in a number of ultrastructural features, (ii) in the pattern of their intralobular distribution, and (iii) in their presence in the spleen and peripheral blood.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00212219
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  • 59
    Digitale Medien
    Digitale Medien
    Bone morphology of weanling rats from dams subjected to fluoride (1983)
    Springer
    Cell & tissue research 233 (1983), S. 689-691 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Fluoride ; Progeny ; Bone ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Femurs of weanling rats from third-pregnancy litters of dams given 150 ppm fluoride in the drinking water were examined by light- and scanning-electron microscopy. Under the conditions of the experimental procedure, no pathological changes were seen in the femurs as a result of maternal ingestion of fluoride. These results indicate that the amount of fluoride crossing the placenta and mammary gland was insufficient to produce significant morphological changes in the bones of 3-week-old rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00212235
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  • 60
    Digitale Medien
    Digitale Medien
    Ultrastructural characteristics of vasopressin-containing neurons in the paraventricular nucleus of the hypothalamus (1983)
    Springer
    Cell & tissue research 234 (1983), S. 125-134 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Vasopressin ; Immunocytochemistry ; Electron microscopy ; Hypothalamus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Vasopressin-containing neurons, identified by immunocytochemistry, are located predominantly in the posterior magnocellular division of the paraventricular nucleus of the rat hypothalamus. By electron microscopy, the immunoreaction product is seen within the cell bodies and neuronal processes. In the perikarya and dendritic processes, the immunoreactive material is associated primarily with neurosecretory granules. Axonal processes, identified by their content of microtubules and accumulation of neurosecretory granules, show the immunoreaction product in association with both of these organelles. Afferent axo-dendritic, axo-somatic and putative axo-axonic synapses with immunostained vasopressinergic neurons can be identified. The presynaptic profiles do not contain immunoreactive material. This study contributes to the ultrastructural characterization of vasopressinergic neurons in the paraventricular nucleus and of their afferent synaptic input.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217406
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  • 61
    Digitale Medien
    Digitale Medien
    Light- and electron-microscopic study on the maturation of the primary portal plexus during the perinatal period in rats (1983)
    Springer
    Cell & tissue research 234 (1983), S. 179-191 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypothalamo-hypophysial system ; Capillaries ; Ontogenesis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The maturation of the capillaries of the primary portal plexus in rats during the perinatal period has been studied lightand electronmicroscopically. The number of capillaries covering the median eminence and of those invading the nervous tissue (capillary loops) increases significantly with age. Capillary loops were observed as early as the 18th fetal day. The mitotic divisions of the endothelial cells within the preexisting capillaries seem to be the main reason for the vascular growth. Immature capillaries with a characteristic narrow lumen are surrounded by a fuzzy basal lamina; their wall is formed by a generally expanded endothelium with rather sparse organelles and inclusions, and by minute flattened areas. The maturation of the capillary results in a progressive spread of flattened endothelium followed by an enlargment of the capillary lumen. Moreover, a rising concentration of organelles and inclusions, relatively numerous luminal microvilli, and a dense and uniform basal lamina become noticeable as capillary differentiation proceeds. These data are thought to reflect the progressive increase in the metabolic activity of the endothelium as well as the establishment of capillary patency during the perinatal period of rats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217411
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  • 62
    Digitale Medien
    Digitale Medien
    Circadian alterations in tubular structures on the outer mitochondrial membrane of rat hepatocytes (1981)
    Springer
    Cell & tissue research 214 (1981), S. 519-527 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mitochondria ; Tubular structures ; Hepatocytes ; Circadian changes ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Subcellular structures of hepatocytes were examined at 11.00 h and 23.00h (light cycle: 06.00h–18.00h) in four adult male Wistar rats (AF/Han) per time period. 1. The volume density of mitochondria in the cytoplasm of hepatocytes obtained from peripheral parts of liver lobules shows a statistically significant difference between the two time periods examined. 2. Tubular structures arising from the outer mitochondrial membrane are clearly demonstrated. Their cisternae are continuous with the interspaces between outer and inner mitochondrial membranes. 3. These tubular structures often open directly into the cisternae of rough or smooth-surfaced endoplasmic reticulum (rER and sER) and form a “bridge” between the endoplasmic reticulum and mitochondria. 4. At 11.00 h, the rER connected with the tubular structures often possesses very few ribosomes; at 23.00 h, the amount of ribosomes on the rER is substantially greater. Furthermore, at 23.00h ribosomes are also occasionally found on the membranes of the tubular structures. 5. The incidence of tubular structures on the outer membrane of mitochondria varies significantly between the two time periods. 6. The changing pattern of the volume density of mitochondria in the cytoplasm parallels that of the incidence of the tubular structures, i.e., both are high during the active phase and low during the resting phase of the rat. 7. These results suggest that the tubular structures may play an important role in protein transport between the endoplasmic reticulum and mitochondria, and in the rearrangement of rER during a 24-h period.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233492
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  • 63
    Digitale Medien
    Digitale Medien
    The relationship between the nuage and the chromatoid body during spermatogenesis in the Rat (1981)
    Springer
    Cell & tissue research 215 (1981), S. 425-430 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Nuage ; Chromatoid body ; Spermatogenesis ; Germ cell determination ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cytoplasmic structures ultrastructurally similar to the nuage are present in the cytoplasm of all spermatogenic cells in adult rats. The nuage is a discrete organelle which should not be confused with the chromatoid body. In step 7–8 spermatids transient contact is established between the nuage and the chromatoid body. This indicates a very specific recognition of the nuage by the chromatoid body. It is suggested that the nuage and the chromatoid body are separate cell organelles the functions of which are somehow related to each other.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239125
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  • 64
    Digitale Medien
    Digitale Medien
    Intraepithelial blood vessels in the vomeronasal neuroepithelium of the rat (1981)
    Springer
    Cell & tissue research 215 (1981), S. 465-473 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Vomeronasal organ ; Olfaction ; Intraepithelial blood vessels ; Rat ; Transmission electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Epithelial-vascular relationships are established during the development of the vomeronasal neuroepithelium of the rat. Special attention is given to the fine structure of the endothelial wall of intra-epithelial vessels, to ultrastructural aspects of the neuronal-vascular relationships, and to the appearance of inclusion bodies in the neuronal cells adjacent to these vessels. The neuronal perikarya surrounding the blood vessels are filled with highly developed smooth endoplasmic reticulum. Possible functional implications of the vascularization of the neuroepithelium of the vomeronasal organ in mediating olfacto-endocrine relationships are discussed. It is suggested that the intra-epithelial blood vessels are at least supportive and nutritive in nature, while their implication in an olfacto-endocrine connection remains obscure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233523
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  • 65
    Digitale Medien
    Digitale Medien
    The rat pituitary cleft: A correlated study by scanning and transmission electron microscopy (1981)
    Springer
    Cell & tissue research 215 (1981), S. 515-529 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pituitary ; Rathke's cleft ; Ultrastructure ; Scanning electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary SEM reveals that the inner surface of the pituitary cleft is lined by a continuous layer of marginal cells possessing microvillous and ciliated apical surfaces. The ciliated cells are more numerous on the posterior side (toward the pars intermedia) than on the anterior side of the cleft (toward the pars distalis). In contrast small infoldings (crypts) were occasionally noted only on the marginal layer covering the distal part of the hypophysis. In some areas of the cleft the surface features of the marginal cells are rather similar to the epithelial cells populating the upper parts of the respiratory tract in their topography and distribution. In other regions they also show striking similarities with the ependymal cells (tanycytes) lining the lateral recesses of the 3rd ventricle and the infundibular process with which the pituitary cleft has a very close topographical relationship. The parenchymal cells of the pars distalis are closely related to the flattened marginal cells of the cleft. The intercellular spaces of the pars distalis form a three-dimensional labyrinthic series of cavities continuous with the submarginal spaces of the cleft. Further SEM and TEM results demonstrate that the majority of the microvillous marginal cells lining both sides of the cleft possess surface features such as bulbous protrusions, laminar evaginations and large cytoplasmatic vacuoles, which are very likely the expression of an active transport of fluids. On the basis of these results it is concluded that the fluid-like material (colloid) present in the pituitary cleft is mainly derived from the fluids contained in the lacunar spaces of the pars distalis. Thus, marginal cells by absorbing fluids from the cleft by active endocytosis, may transport to the pars intermedia material (or hormones) produced in the distal part of the gland and vice versa. The cilia present on many marginal cells, based on their 9+2 tubular pattern, possess a kynetic role. This is very similar to that shown by the ciliated cells of the ependyma lining the brain ventricles. The occurrence of ciliated cells within the pituitary parenchyma (mainly in the follicles) suggests that they probably arise from the ciliated cells populating the marginal layer of the cleft and with which the parenchyma cells are closely related.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00233528
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  • 66
    Digitale Medien
    Digitale Medien
    Ultrastructure of neurons in the ventromedial nucleus or the hypothalamus in ovariectomized rats with or without estrogen treatment (1981)
    Springer
    Cell & tissue research 217 (1981), S. 451-470 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ventromedial nucleus ; Ultrastructure ; Estrogen effects ; Secretory product ; Lordosis ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the ventrolateral and dorsomedial subdivisions of the ventromedial nucleus (VMN) of the hypothalamus was examined in ovariectomized/control and ovariectomized/estrogen-treated rats to compare neurons of these areas to other neurons (specifically the ventrolateral thalamus), and to determine the effects of estrogen on these cells. The neurons of the VMN contain a large nucleus with a prominent nucleolus, rough endoplasmic reticulum (RER), polysomes, a Golgi complex, coated, uncoated and dense-cored vesicles, lysosome-like bodies, inclusion bodies, multivesicular bodies, whorl bodies and myelin figures. Similar organelles were present in the neurons of the ventrolateral thalamus, although polysomes were more prominent, and the cells lacked dense-cored vesicles in the perikarya. Differences in the cells of the VMN between ovariectomized/control and ovariectomized/estrogen-treated rats included a more conspicuous stacking of the RER and greater number of dense-cored vesicles in the estrogen-treated group in both the ventrolateral and dorsomedial subdivisions. In both areas the differences were statistically significant, although more marked in the ventrolateral subdivision. In both VMN subdivisions, the increased stacking of the RER could be correlated with the greater number of dense-cored vesicles and may reflect increased biosynthesis of a secretory product.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00219357
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  • 67
    Digitale Medien
    Digitale Medien
    Morphological studies on neuroglia (1981)
    Springer
    Cell & tissue research 218 (1981), S. 75-86 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Microglia ; Macrophages ; Chemical lesion ; Kainic acid ; Hippocampus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Light-and electron-microscopic investigations of kainic acid-induced lesions revealed a marked macrophage response and “microgliocytosis”. The hematogenous origin of reactive elements, such as brain macrophages and “microglia-like reactive cells”, was demonstrated when blood phagocytes were labeled with carbon particles or horseradish peroxidase prior to induction of the kainic acid-lesion. The induced lesion showed a proliferation of microglial cells, which led to a state of “microgliocytosis” in the later stage of lesioning. Since it is now generally accepted that microglial cells in the state of “microgliocytosis” are derived from the “microglia-like reactive cells”, proliferated microglial cells in the brain lesions are probably of hematogenous origin. The relationships among the brain macrophages, the “microglia-like reactive cells” and the intrinsic microglial cells are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210092
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  • 68
    Digitale Medien
    Digitale Medien
    The hypothalamo-hypophysial system of hypophysectomized rats (1981)
    Springer
    Cell & tissue research 218 (1981), S. 607-622 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Hypophysectomy ; Median eminence ; Light and electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The median eminence (ME) of hypophysectomized rats was studied by means of light and electron microscopy. Paraldehyde-fuchsin (PAF)-positive material is seen in the external zone (EZ) of the ME 2–5 days after the operation. Its amount gradually increases especially in the caudal part of the ME during the following few days. Some PAF-positive fibers make contact with the subependymally located blood capillaries. In the most caudal region of the recessus infundibuli they penetrate into the third ventricle. PAF-positive material decreases markedly from the ME of rats two months after hypophysectomy and exposure to a 1% salt load. Fibers of types A1, A2 and B containing granules of 120–220 nm, 100–150 nm and 80–100 nm in diameter, respectively, are seen in the EZ of the ME in hypophysectomized rats, although almost exclusively A2- and B-type structures make contact with the primary portal capillaries in intact animals. All types of neurosecretory fibers establish contact with the subependymal nonfenestrated blood capillaries and penetrate the recessus infundibuli. Some neurosecretory terminals of different types make direct contact with the glandular cells of the pars tuberalis or are separated from them by a thin basal lamina. It is assumed that mainly neurosecretory fibers of types A2 and B are permanently connected with the primary portal capillaries in the EZ of the ME in intact mammals, while the overwhelming majority of fibers of A1-type shows ingrowth during the course of postoperative reparation. The possible physiological significance of the described changes is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210119
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  • 69
    Digitale Medien
    Digitale Medien
    Immunocytochemical investigation of the subcommissural organ in the rat (1981)
    Springer
    Cell & tissue research 218 (1981), S. 659-662 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Peptides ; Subcommissural organ ; Secretion ; Immunocytochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The results of a preliminary immunocytochemical investigation on the subcommissural organ (SCO) in rats show that (1) Reissner's fiber (RF) or essential compounds of the RF are produced by the SCO, (2) the immunoreactive material is produced in the epithelial cells of the SCO as well as in the hypendymal cells, and (3) the immunoreactive material of the SCO belongs to a category of endogenous peptides to date not demonstrable immunocytochemically in other brain structures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210122
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  • 70
    Digitale Medien
    Digitale Medien
    p-Chlorophenylalanine-induced proliferation of the seminal vesicle epithelium (1981)
    Springer
    Cell & tissue research 219 (1981), S. 159-172 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Seminal vesicles ; Proliferation ; Autoradiography ; Biochemistry ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Intraperitoneal injection of p-chlorophenylalanine (pCPA) methylester (100 mg/kg body weight) results in an activation of the lysosomal system of the secretory cells in the rat seminal vesicle and an elevation of the activities of lysosomal enzymes within 15 min following the injection. Large autophagic vacuoles are formed, sequestering rough endoplasmic reticulum and part of the Golgi apparatus within 2 h. Shortly after the activation of the lysosomal system an elevation of both DNA and protein synthesis is measured biochemically. 6 h subsequent to the injection a wave of mitoses of the secretory cells begins, reaching a maximum 6 h later and then declining within 3 h. About 12 h following the injection a second rise in lysosomal activity begins, declining within 24 h. The entire sequence of lysosomal and proliferative activities is inhibited in antiandrogen-pretreated rats. Deduced from these findings the following hypothesis of growth regulation of the accessory sex glands is advanced: enhanced loss of intracellular material during autophagocytosis diminishes the intracellular concentration of a substance curtailing cell division below its effective threshold resulting in division of the secretory cells. The prerequisites of this mechanism are (i) a sufficient distributive capacity of the stroma for hormones (androgens) and metabolic precursors, and (ii) sufficient capacity of the basal cells for transporting the precursors to the secretory cells. Sloughing of the secretory cells separates them from these auxiliary structures (stroma and basal cells) and enables the basal cells to divide.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210025
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  • 71
    Digitale Medien
    Digitale Medien
    Cytochemical analysis of intracellular calcium distribution in the anterior pituitary of the rat (1981)
    Springer
    Cell & tissue research 220 (1981), S. 191-200 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Pituitary ; Calcium ; Pyroantimonate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In an attempt to assign morphologic identities to previously distinguished functional calcium compartments in the anterior pituitary of the rat, we employed the potassium pyroantimonate technique for cation localization. Tissues were incubated for In at 37°C in control medium; with 10mM theophylline; or with depolarizing amounts of potassium. Precipitate was quantified on photomicrographs of tissue prepared for electron microscopy with a Talos Systems Digitizer. The nature of the electron dense precipitate was dependent on the experimental state of the tissue. Treatment with 5 mM EGTA abolished the dense precipitate. Electron microprobe analysis also confirmed that calcium was the predominant cation in the observed precipitate. The most significant changes in precipitate deposition occurred along the plasma membrane, the limiting membrane of secretory granules and within mitochondria. Dense precipitate was present along the plasma membrane only in cells treated with potassium. Control tissue exhibited higher levels of precipitate associated with the limiting membrane of secretory granules than either theophylline-treated or potassium-treated tissue. Mitochondria contained more precipitate in potassium-treated tissue than in controls; the mitochondria of theophylline-treated tissue contained intermediate levels of precipitate. Addition of either theophylline or depolarizing amounts of potassium has been associated with hormone secretion in anterior pituitary tissue of normal rats. Kinetic studies in our laboratory indicate that intracellular calcium shifts occur. The pyroantimonate technique is useful in verifying morphologically the calcium compartments involved in shifts in intracellular calcium.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00209977
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  • 72
    Digitale Medien
    Digitale Medien
    Monosodium glutamate-induced lesions in the rat cingulate cortex (1981)
    Springer
    Cell & tissue research 220 (1981), S. 239-250 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Cingulate cortex ; Monosodium glutamate ; Neurotoxic amino acid ; Cell degeneration ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The brains of neonate albino rats were examined with the light and electron microscope following subcutaneous administration of monosodium glutamate (MSG). In addition to lesions in areas known to be vulnerable to glutamate, such as the arcuate nucleus of the hypothalamus, distinct areas of necrotic tissue were detected in the granular portion of the retrosplenial cingulate cortex. The affected cells display the cytological features characteristic of MSG-lesioned brain tissue, including vacuolization of the endoplasmic reticulum and clumping of chromatin. Numerous pyknotic nuclei can be detected as early as 3 h following treatment. The possible causes of the lesion, particularly the role that may be played by astrocytes, are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210506
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  • 73
    Digitale Medien
    Digitale Medien
    A comparison of neuropeptide immunocytochemistry in fluid-fixed and freeze-dried brains (1981)
    Springer
    Cell & tissue research 220 (1981), S. 223-230 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Immunocytochemistry ; Freeze-dried brain ; Fluid-fixed brain ; LHRH ; Somatostatin ; Neurophysin ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunocytochemical staining of luteinizing hormone-releasing hormone (LHRH), somatostatin, and neurophysin was compared in rat brains fixed with 1) formalin, 2) Bouin's solution, 3) freeze-dried (FD), or 4) freeze-dried + paraformaldehyde vapor perfused (FDV). The distribution of LHRH fibers was similar in all preparations; however, beads of granular reaction product often appeared finer and more numerous in the median eminence of FD- and FDV brains. Positively stained LHRH perikarya were not observed in any of the preparations. In contrast, somatostatin-immunoreactive perikarya were present in the fluid-fixed and FD brains, although few were observed in FDV brains. Somatostatin-immunoreactive fibers were present in all preparations, but appeared most numerous in the median eminence of FD brains. Staining of neurophysin-containing perikarya and fibers was similar in all preparations. These observations suggest that the FD brain can provide a suitable tissue substrate for immunocytochemistry, demonstrating staining comparable to or surpassing that of more conventional preparations. However, staining of antigens in FD brain was not uniformly successful and may depend on stereochemical characteristics of each antigen as well as properties of the primary antisera used in the staining procedure.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00210504
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  • 74
    Digitale Medien
    Digitale Medien
    Morphological studies on neuroglia (1983)
    Springer
    Cell & tissue research 229 (1983), S. 85-95 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Amoeboid microglial cells ; Brain macrophages ; Immunohistochemistry ; Macrophage antiserum ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Immunohistochemical studies with the use of the peroxidase-antiperoxidase (PAP) method revealed that “amoeboid microglial cells”, in the brains of neonatal rats and “brain macrophages” in lesioned brains of adult rats react positively to an antiserum raised against macrophages. In brains of neonatal rats, “amoeboid microglial cells” stained by means of the PAP-method were observed in the corpus callosum, internal capsule, dorso-lateral region of the thalamus, subventricular zone of the lateral ventricle, and the subependymal layer of the ventricular system. These cellular elements were not detected in brains of rats aged 21 days or older. Resting microglial cells displaying a typical ramified structure were not specifically stained. Cells reacting positively to the macrophage antiserum appeared (i) in the cerebral cortex of adult rats following placement of a stab wound, or (ii) in the hippocampal formation after kainic acid-induced lesions; in the damaged areas immunoreactive cells exhibited the typical features of “brain macrophages”. “Brain macrophages” and “amoeboid microglial cells” are considered to belong to the class of exudate macrophages derived from blood monocytes. Thus, elements of hematogenous origin do exist in the intact brain parenchyma of neonatal rats and in lesioned brains of adult rats. The relationship between brain macrophages and resting microglial cells is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217882
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Digitale Medien
    Digitale Medien
    Regeneration of splenic tissue after autologous subcutaneous implantation: Homing of T- and B- and Ia-positive cells in the white pulp of the rat spleen (1983)
    Springer
    Cell & tissue research 229 (1983), S. 97-107 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Splenic implants ; Immunoperoxidase technique ; Lymphocyte homing ; Interdigitating cells ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The localization of T-and B lymphocytes and interdigitating cells (IDC) was investigated during the regeneration process of splenic implants. For this purpose a two-step immunoperoxidase technique was used to visualize T-cell antigen, immunoglobulins and Ia-antigen on cryostat sections. The specific localization of the repopulating lymphocytes occurred simultaneously with the development of non-lymphoid elements characteristic for the different compartments of the white pulp, i.e., the periarteriolar lymphocyte sheaths (PALS) and follicles. The marginal zone (MZ) developed after the PALS and primary follicles, but before germinal center reactions were found. During ontogeny, however, the development of a broad MZ precedes the formation of follicles. This difference in sequence of events is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217883
    Standort Signatur Erwartet Verfügbarkeit
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  • 76
    Digitale Medien
    Digitale Medien
    Effect of adrenalectomy and administration of hypertonic saline on the content of aldehyde fuchsin-positive neurosecretory material and posterior lobe hormones in the median eminence and the neural lobe of rats (1983)
    Springer
    Cell & tissue research 228 (1983), S. 127-138 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Vasopressin ; Oxytocin ; Neurophysin ; Neurohypophysis ; Adrenalectomy ; Osmotic stress ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The influence of adrenalectomy and administration of hypertonic saline on the amount of vasopressin, oxytocin, and neurophysin contained in the median eminence and the neural lobe of rats was studied by means of the following methods: (i) morphometric and microphotometric analyses of aldehyde fuchsin-stained histological sections of the neurohypophysis; (ii) immunohistochemical demonstration of vasopressin, oxytocin, and neurophysin in the neurohypophysis, and (iii) radioimmunological measurement of vasopressin and oxytocin in extracts of the median eminence and the neural lobe. Adrenalectomy increases the amount of vasopressin and neurophysin in the external layer of the median eminence but does not change the content of oxytocin. It has no influence on the amount of vasopressin, oxytocin, and neurophysin demonstrable in the inner layer of the median eminence and in the neural lobe two weeks after the operation. Hypertonic saline markedly diminishes the vasopressin, oxytocin, and neurophysin content of the inner layer of the median eminence and the neural lobe but reduces only slightly, if at all, the amount of vasopressin and neurophysin in the outer layer of the median eminence. The findings support the concept that osmotic stress reduces only the vasopressin and oxytocin content of the hypothalamus-neural lobe system and has no or only little influence on the vasopressin content of the outer layer of the median eminence.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00206271
    Standort Signatur Erwartet Verfügbarkeit
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  • 77
    Digitale Medien
    Digitale Medien
    Freeze-fracture study of the rat parathyroid gland under hypo- and hypercalcemic conditions, with special reference to secretory granules (1983)
    Springer
    Cell & tissue research 228 (1983), S. 219-230 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Rat ; Parathyroid ; Freeze-fracture ; Storage granule ; Exocytosis ; Endocytosis ; Discharged secretory granule
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Freeze-fracture images of the parenchymal cells in the parathyroid gland of rats were observed after vitamin D2 plus calcium chloride-suppression and EGTA-activation of secretion. In cells of the suppressed glands, large bulges protruded from the Golgi cisternae, and large granules with a stalk, which are identified as storage granules, suggest that, during maturation, some storage granules may be connected by long tubules with the Golgi cisternae and supplied with secretory products from the Golgi cisternae via these tubules. In the activated glands, presumptive exocytotic and endocytotic specializations of intramembranous particles of the parenchymal cell plasma membrane were frequently observed. In addition, elevations and complementary shallow depressions of various shape and extent were occasionally encountered in the intercellular space. From their morphological characteristics it was concluded that these originated from secretory granule cores, which are discharged from the parenchymal cells into the intercellular space by exocytosis, and it was suggested that discharged granule cores may retain their spherical shape until they fuse to form a flat conglomerate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00204874
    Standort Signatur Erwartet Verfügbarkeit
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  • 78
    Digitale Medien
    Digitale Medien
    Morphometry of the small intestinal enterocytes of the fasted rat and the effects of colchicine (1983)
    Springer
    Cell & tissue research 231 (1983), S. 289-299 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Enterocytes ; Microtubules ; Colchicine ; Cell membrane ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The function of the microtubules that are present in the villus enterocytes of the mammalian small intestine is virtually unknown. In order to advance our knowledge about enterocyte microtubules, a quantitative ultrastructural comparison was carried out on enterocytes from rats injected intraperitoneally with colchicine (0.5 mg/100 g body weight) in saline and from rats injected with saline alone. Our morphometric and stereologic study demonstrates that colchicine treatment results in 1) an absolute decrease in microtubules, 2) a reduction in microvilli, essentially in length, 3) an increased thickness of the terminal web, 4) an increase in total lysosomal volume, apparently by an increased number of smaller lysosomes, and 5) a decrease in the number of Golgi lamellae. These results along with those from other studies suggest to us that enterocyte microtubules are involved in the biogenesis of microvillus plasma membrane. Our morphometric data from the saline-treated rats essentially agree with comparable data from other studies. However, comparison with comparable data from hamster enterocytes demonstrates species differences.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00222181
    Standort Signatur Erwartet Verfügbarkeit
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  • 79
    Digitale Medien
    Digitale Medien
    Effects of norepinephrine and dibutyryl adenosine 3′, 5′-cyclic monophosphate on the ultrastructure of pineal cells in monolayer culture (1981)
    Springer
    Cell & tissue research 216 (1981), S. 181-191 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Pineal gland ; Monolayer culture ; N-acetyl transferase ; Ultrastructure ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary To determine how neural influences control the function of the pineal gland, morphological and biochemical relationships after pharmacological treatment have been studied in rat pineal cells in monolayer cultures. Norepinephrine (NE) and dibutyryl cyclic 3′,5′-adenosine monophosphate (dBcAMP) treatment of cells that had been in culture for 5 and 21 days produced a stimulation in the enzyme activity of serotonin N-acetyl transferase, an enzyme important in indole synthesis. NE and dBcAMP also produced morphological changes which were dependent on the time of cells in culture. When 5 day-cultures were treated with NE and dBcAMP, light and dark cells were noted and endoplasmic reticulum increased and became more organized. Only dBcAMP treatment at 5 days produced an increase in dense granules and an elongation of cytoplasmic processes. Treatment of 21 day-cultures with dBcAMP also produced an increase in cytoplasmic processes while treatment with NE produced an increase in the synaptic ribbons and clear vesicles within the processes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234553
    Standort Signatur Erwartet Verfügbarkeit
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  • 80
    Digitale Medien
    Digitale Medien
    Morphological studies on neuroglia (1981)
    Springer
    Cell & tissue research 216 (1981), S. 569-580 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Glial response ; Chemical lesion ; Kainic acid ; Hippocampus ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The cellular response of non-neuronal elements of the pyramidal cell layer of the rat hippocampus, especially the area CA 3, was observed electron microscopically following destruction of this formation by means of intraventricular administration of kainic acid (KA). The neuroglial cell types responding to the KA-induced lesion included astrocytes and the “microglia-like reactive cells”. In addition, numerous brain macrophages appeared in the damaged area CA 3. Oligodendrocytes and pericytes revealed no morphological changes. Swollen astrocytes were seen in the KA-induced lesion during the early stage. Glial filaments gradually developed in the soma and cell processes of these cells. Brain macrophages were seen in the KA-induced lesion during the early stage; they gradually decreased in number with time. Numerous small cells displaying a dark nucleus appeared in the damaged area CA 3 during the first two days after the KA-administration, and gradually increased in number. During the later stage this cell type could hardly be distinguished from the intrinsic microglial cells. It is open to discussion whether this cell type originates from the intrinsic microglial cells or from the hematogenic monocytes; therefore it is designated as “microglia-like reactive cell” in the present study.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238652
    Standort Signatur Erwartet Verfügbarkeit
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