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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of prenatal irradiation on the testis are well documented, but less is known about its effects on epididymal differentiation. Pregnant rats were irradiated on the 18th day of gestation. The increase in microfilaments and lipid inclusions in the epithelial cells, in favor of a direct radiation effect, is maximal at birth and disappears thereafter. Narrow cells and clear cells show a normal differentiation pattern. On the other hand, the principal cell maturation is largely altered. The synthesis capacities are decreased based on a reduction in the size of the Golgi apparatus and the smooth endoplasmic reticulum. The aspects of invaginations of the apical plasmalemma, coated vesicles and multivesicular bodies are not modified, suggesting normal absorption functions. The epithelial basement membranes become irregular and thicker than normal, enfolding the basal part of the epithelial cells. The basement membrane proteoglycans, demonstrated by the cationic marker polyethyleneimine, are irregularly distributed in contrast to the normal pattern. These modifications of the principal cells and the basement membrane are more prominent in the proximal epididymis. This suggests a differential maturation dependence of the epithelial cells on the luminal factors, normally secreted by the testis, and likely disturbed by prenatal irradiation which leads to germ cell degeneration, and then to a new balance in the seminiferous epithelium.
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PMID:Ultrastructural study of epithelial cells and basement membrane. Differentiation of the rat epididymis after prenatal irradiation. 295 12

The present study was undertaken to evaluate the effects of the chemosterilant 2,4-dinitrotoluene (DNT) on the rat testis. Adult male rats were fed control, or 0.1%, or 0.2% DNT for 3 weeks. An ultrastructural study of the testes was performed, serum was assayed for testosterone and gonadotropins, and sperm reserve count was determined. A marked change in Sertoli cell morphology was found after 3 weeks of 0.2% DNT exposure. Varying sized vesicles associated with swollen mitochondria and distended endoplasmic reticulum were visible in cells from DNT-treated animals. Circulating levels of follicle stimulating hormone and luteinizing hormone were increased in 0.2% DNT-treated animals. Reduced weights of the epididymides and decreased epididymal sperm reserves were observed in DNT-treated animals. These results indicate that DNT is capable of inducing testicular injury, of directly or indirectly disturbing pituitary function, and of exerting a toxic effect at the late stages of spermatogenesis. These findings suggest that a locus of DNT action is the Sertoli cell, resulting in both inhibition of spermatogenesis and changes in testicular-pituitary endocrine activity.
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PMID:Reproductive toxicity of 2,4-dinitrotoluene in the rat. 313 40

The epididymal epithelium from adult castrated and androgen supplemented, castrated rhesus monkeys was examined with transmission electron microscope. Ninety days after bilateral castration the tubular diameter of all the regions of the epididymis, viz. the initial segment, caput, corpus and cauda portions of epididymis was reduced and was accompanied by a drop in cell size. There was a marked decrease in the number and size of microvilli on the luminal surface. The invaginations of apical membrane into the cell cytoplasm became less prominent. There was a reduction in the amount of smooth and rough endoplasmic reticulum, and Golgi complex. Mitochondria accumulated in the apical cytoplasm. Several vacuoles often associated with lipofuscin pigment granules were common in the cytoplasm. These findings suggest a reduction in both the absorptive and secretory functions of the principal cells. Following androgen replacement therapy for 30 days in monkeys that were castrated 60 days earlier there was a recovery of structural features in the epithelium to near normal state.
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PMID:Ultrastructural changes in the principal cells of epididymis of adult rhesus monkey (Macaca mulatta) after castration and androgen replacement therapy. 325 59

Epididymal adipose tissue in the rat is generally considered to be "pure" white adipose tissue (WAT) with a characteristic structure and function. Previous studies in cats have, however, indicated that adipose tissue with the morphological appearance of WAT could be converted into a tissue with the morphological appearance of brown adipose tissue (BAT) by intermittent cold stress. The present electron microscopic and morphometric study describes the effect of intermittent cold stress on the epididymal WAT of young rats. The tissue volume decreased markedly as did the lipid content. The mitochondrial volume increased dramatically. The extracellular matrix was vastly reduced as was the thickness of the plasma membrane, and the number of gap junctions between adipocytes increased markedly. Indications of neoinnervation and neovascularization were observed. A great abundance of preadipocytes indicated proliferative activity of the endothelium. The low amount of lipid droplets and a relative abundance of smooth and rough endoplasmic reticulum. Golgi apparatus, and lysosomes in the epididymal WAT of cold-stressed rats gave the cells the morphological appearance of young adipocytes or preadipocytes whereas the hypertrophic and hyperplastic mitochondria, the relative paucity of ribosomes on lipid droplet membranes, and the increased innervation and vascularization gave the cells the morphological characteristics of brown adipose tissue.
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PMID:Epididymal white adipose tissue after cold stress in rats. I. Nonmitochondrial changes. 326 8

Sperm maturation and storage occur in a unique milieu created in large part by the epididymal epithelium. To learn more about the interaction of the epididymal epithelial cell with both luminal and systemic environments, we now report on the preparation and characterization of epididymal epithelial cell plasma membranes. A preparation enriched for epididymal epithelial cell plasma membranes was isolated from collagenase-digested epididymal tubule fragments by hand-Dounce homogenization, differential centrifugation, and sucrose gradient centrifugation. The final membrane fraction was enriched 11-fold for the plasma membrane marker 5'-nucleotidase; 2.6-fold for the lysosomal marker acid phosphatase, and 3-fold for the Golgi marker thiamine pyrophosphatase. No enrichment was observed for mitochondrial or endoplasmic reticulum enzyme markers. Specific and saturable transferrin-binding activity was also detected in the final preparation. Electron microscopy revealed the presence of vesicles and sheets of membranes as well as an occasional Golgi apparatus. The plasma membrane fraction was used to generate monoclonal antibodies. Of 102 wells exhibiting growth, 12 were positive by immunofluorescent staining of frozen sections. Ten of these recognized determinants in epithelial cells, and 2 stained peritubular smooth muscle cells. Most of the epithelial cell-specific antibodies stained brush border alone or in combination with the basolateral plasma membrane. Three antibodies stained the Golgi apparatus. Most antibodies were specific for particular epididymal regions, 3 also recognized determinants in the kidney, and 1 stained residual bodies in the testis.
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PMID:Isolation and characterization of epididymal epithelial cell plasma membranes. 336 69

The epididymal epithelial ultrastructure has been described in the adult male North American opossum, Didelphis virginiana. Morphological results have suggested that absorptive activity is prominent in the proximal epididymal region by virtue of numerous microvilli, an endocytotic complex, dense granules, and multivesicular bodies in the apical cytoplasm. In contrast, the middle and distal epididymal regions exhibit ultrastructural features indicative of protein synthesis such as large invaginated euchromatic nuclei, large nucleoli, and increased amounts of granular endoplasmic reticulum. It is in the middle and distal epididymal regions where sperm head rotation and sperm pairing take place. Epididymal delta 4-3-ketosteroid-5 alpha-oxidoreductase (5 alpha-reductase) activity also has been measured. It has been found that the level of enzyme activity differs significantly (p less than 0.01) between the proximal, middle, and distal epididymal regions. Enzyme-specific activity has been found to be highest in the middle region (47.6 +/- 5.4 picomoles 5 alpha-reduced androgens formed/b/mg protein), lower in the distal region (18.3 +/- 0.7 picomoles 5 alpha-reduced androgens formed/b/mg protein), with little activity (2.4 +/- 1.2 picomoles 5 alpha-reduced androgens formed/h/mg protein) found in the proximal epididymal region. This regional distribution of enzyme activity differs markedly from that reported for eutherian mammals. Both the suggested epididymal protein synthetic and secretory activity and the level of epididymal 5 alpha-reductase activity appear to correlate regionally with the morphological changes that occur in the opossum spermatozoa as they transit the epididymis.
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PMID:Unique regional distribution of delta 4-3-ketosteroid-5 alpha-oxidoreductase and associated epididymal morphology in the marsupial, Didelphis virginiana. 367 95

The epididymis of the bull was divided into six regions, and morphological differences between regions were studied. The epithelium of all regions contained four cell types: principal and basal epithelial cells, and intraepithelial lymphocytes and macrophages. The epithelium of regions II-V also contained a few apical cells. Principal cells of all regions possessed an endocytotic apparatus including stereocilia underlain by canaliculi, coated vesicles, and subapical vacuoles (up to 1 micron in diameter); however, large vacuoles with a flocculent content and multivesicular bodies (up to 5 microns in diameter) were most numerous in regions II, III, and IV. The unique features of principal cells of region I were the presence of well-developed Golgi bodies, few lipid droplets, and whorls of smooth endoplasmic reticulum in the supranuclear cytoplasm. Numerous mitochondria, distended cisternae of rough endoplasmic reticulum, and dense granules characterized the infranuclear cytoplasm of the principal cells of regions II-VI; however, these features were more developed in region V. Apical cells were characterized by the apical location of the nucleus, many mitochondria in the apical cytoplasm, and few microvilli at the luminal border. Basal cells with few cytoplasmic lipid droplets were present throughout the length of the epididymis but appeared more numerous in region V. Intraepithelial lymphocytes were present at all levels of the epithelium but were never seen in the lumen. Intraepithelial macrophages containing heterogeneous granules, eccentric nuclei, and pseudopods were invariably seen near the basal area of the epithelium in all regions. These observations are discussed in an effort to define the role of each cell type in the epididymal epithelium.
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PMID:Morphology of the bovine epididymis. 391 58

The secretory process for glycoproteins in principal cells of the mouse caput epididymis was studied by electron microscope radioautography at intervals after exposure to [3H] fucose in vitro. The large Golgi apparatus showed very heavy labeling at the initial interval, followed by a steady decline in percent of grains and relative grain concentrations. Conversely, the epididymal lumen and the apical cell surface began low and increased in radioactivity at the 30-min interval. The extensive sparsely granulated endoplasmic reticulum showed modest increases in percent of grains and relative grain concentrations 30 min after administration of the percursor. Subdivision of the sparsely granulated reticulum into "intermediate" profiles (some ribosomes attached to the membranes) and "smooth" profiles (lacking ribosomes) showed that this increase was due to silver grains assigned to the smooth portions. After the initial interval, high relative grain concentrations were calculated for vesicles. The results indicate that glycosylation of epididymal secretory glycoproteins occurs in the Golgi apparatus, which is, therefore, not bypassed as its morphological features had suggested. The kinetics of the secretory process in the principal cells includes 15 to 30 min for synthesis of the polypeptide parts of secretory products and addition of sugars in the Golgi apparatus, and a similar time for subsequent release from the Golgi apparatus, transport to the apical end of the cell and discharge to the lumen. Ribosome-studded (intermediate) portions of the sparsely granulated endoplasmic reticulum are probably involved in synthesis of polypeptide parts of secretory products, while vesicles or smooth portions of the sparsely granulated reticulum may play a role in intracellular transport of glycoproteins.
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PMID:Radioautographic analysis of the secretory pathway for glycoproteins in principal cells of the mouse epididymis exposed to [3H] fucose. 398 69

When male rats were given single i.p. injection of 500 mg of L-arginine/100 g body weight, the pancreatic acinar cells were destroyed selectively, without any morphological change of Langerhans' islets. As early as 24 hours after the injection, loss of basophilia, zymogen degranulation, and vacuolar and necrotic changes of the acinar cells were noted. After 3 days, fibroblastic activity and atrophy of pancreatic lobuli were evident. Early electron microscopic findings were changes of the endoplasmic reticulum, such as partial dilatation or vacuolation of the cisternae, usually with loss of ribosomes attached to the membrane. The effect of arginine excess may be ascribed to imbalance of amino acids and subsequent to decrease of protein synthesis in the acinar cells. In the course of this study, fat necrosis with marked infiltration of leucocytes was observed in adipose tissues in peripancreatic, epididymal, omental and retroperitoneal areas. This change correlated closely with the marked necrosis of the pancreas. An increase in the level of lipase in the blood was also demonstrated.
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PMID:Effects of injecting excess arginine on rat pancreas. 619 86

Regional differences in the proximal part of mouse epididymis were reported to provide a morphological baseline for studies on functional zonation of this part that is critical in sperm maturation. Macroscopical, histological, ultrastructural, and histochemical observations permitted us to subdivide this part into five segments, characterized by epithelial height, nuclear position, cytological and histochemical features of principal cells. Segment I corresponded to the initial segment previously described in rodents. Segment II differed from segment I by endoplasmic reticulum (ER) and dictyosomes aspect in principal cells, apical alkaline phosphatase and Ca2+-dependent ATPase activities. Segment III was characterized by spermatozoa package, high content of cells in multivesicular bodies, mitochondria shape, complex interdigitating membranes, and strong periodic acid-Schiff (PAS)-positive cell border. Segments IV and V presented the same cytological features but differed by their esterase activity. In the principal cells of each segment, dense spherical concretions were scattered in ER caveolae. Cells with apical nuclei were classified into two groups. The cells of the first group presented the same morphological and histochemical features as the adjacent principal cells and were scattered in the five segments ("apical cells"). The cells of the second group differed from the others by their goblet shape, a dense cytoplasm, and a high mitochondria succinate-D activity. They presented different cytological and histochemical features depending on their localization in segments I ("narrow cells"), II ("prominent cells"), or III, IV, V ("mitochondria goblet-cells"). The possible relationships between epithelium structure and epididymal functions were herein discussed.
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PMID:Regional differences of the proximal part of mouse epididymis: morphological and histochemical characterization. 646 30


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