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

The ultrastructural changes in langur monkey epididymis prior to and following vasectomy or vasovasostomy were studied. The epididymal epithelium of the intact langur monkey was found to consist mainly of principal cells and basal cells and frequently apical or mitochondria rich cells were found. Besides these cells intraepithelial lymphocytes were also a consistent feature of the epididymal epithelium. Principal cells identified by means of the tuft of the stereocilia on their apical surface, bear well developed Golgi bodies, endoplasmic reticulum, vesicles, vacuoles and multivesicular bodies. This suggests their active involvement in absorption and secretion. Basal cells present at the base of the lamina bear a few cellular organelles and strong interdigitations with the adjacent cells. Apical or mitochondria rich cells were characterized by clusters of mitochondria in the apical region of the cell and few microvilli on their apical surface. Lymphocytes with a large nucleus and a pale rim of cytoplasm were also found at the base of the epithelium. Secretory and absorptive functions of principal cells of the epididymal epithelium were found to be increased after vasectomy, as indicated by bulging of the apical portion of the principal cells and membrane bound structure in the lumen. An extensive increase in the number of lysosomes, vesicles and vacuoles was also observed. An increase in the number of macrophages with spermatozoa remnants in the lumen of epididymis suggests that the principal mechanism for spermatozoa disposal following vasectomy is intraluminal endocytosis by macrophages. Changes following vasectomy persisted in vasovasostomized animals even after 12 months of recanalization, which may contribute to the failure of functional reanastomosis.
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PMID:Ultrastructure of langur monkey epididymidis prior to and following vasectomy and vasovasostomy. 1055 Jul 98

The effects of atrazine exposure on testicular sperm number, epididymal sperm number and motility and alpha-glucosidase activity in the epididymis were studied in Fischer rats. Histological changes in the testicular tissue were followed by light and electron microscopy. Groups of adult animals were treated i.p. with 60 and 120 mg atrazine kg(-1) body wt. twice a week over 60 days. The results indicate a decrease in the body weight and relative weights of pituitary and ventral prostate vs control, measured on the last day of treatment in both treated groups. Testicular sperm number (expressed as number of sperm per 500 Sertoli cells) in atrazine-treated groups increased with the treatment time due to the reduced sperm motility. Therefore atrazine treatment provoked a significant decrease in sperm number and motility in epididymis, measured after the last day of treatment. alpha-Glucosidase activity in the epididymis, after the last day of treatment, showed a decrease in both treated groups vs control values. Histological analysis of testicular tissue from treated rats showed the cell disorganization and cell clusters together with spermatocytes. Electron microscopy presented differently vacuolated cytoplasm, collagen fibre was reduced, Leydig cells were of irregular shape with unequal form and cisternae of rough endoplasmic reticulum were accentuated and softly widened. In Sertoli cell cytoplasm, atrazine treatment provoked degenerative changes. According to the results obtained, it is evident that atrazine exerted morphological changes and a toxic effect on sperm and their motility.
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PMID:Disorders of male rat reproductive tract under the influence of atrazine. 1064 Oct 17

Information on the dynamics of gamete interaction in marsupials is very limited and not available for any species from the major Australian Order Diprotodontia which includes most of the more familiar animals such as kangaroos, possums and the koala. This study addressed this deficiency by examining the ultrastructure of in vivo fertilised eggs from common brushtail possums (Trichosurus vulpecula). Females were superovulated by treatment with 15 IU PMSG and then 4 mg porcine LH 3 days later, and inseminations were performed 910-13 h after LH) using epididymal spermatozoa. Between 33 and 39 h after LH injection females were killed, reproductive tracts excised and the oviduct ampulla segment flushed for eggs. Three of the six eggs examined were fertilised as judged by the presence of sperm remnants in the cytoplasm. On the basis of these eggs it was found that sperm penetration left a large hole in the zona pellucida (ZP), suggesting that sperm zona penetration occurs primarily by the enzymatic action of acrosomal enzymes. Sperm lying within the perivitelline space were lacking both an outer acrosomal membrane and the associated acrosomal contents, while both these structures were found on sperm embedded within the mucoid layer, which is consistent with induction of the acrosome reaction by binding to the ZP. Once inside the egg cytoplasm, the sperm head travelled only a short distance before chromatin decondensation occurred. Fertilised eggs showed signs of cytoplasmic activation including cytoskeleton association with apparently dividing mitochondria and prominent rough endoplasmic reticulum. Unfertilised eggs appeared to be undergoing degenerative changes and lacked any evidence of activation. This study was demonstrated that superovulation and laparoscopic intravaginal artificial insemination provide a system through which perifertilisation events in the possum and other monovular Australian marsupials can be examined experimentally.
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PMID:Ultrastructural observations on in vivo fertilisation in the brushtail possum, Trichosurus vulpecula, following PMSG/LH superovulation and artificial insemination. 1071 49

Acidification of the epididymal lumen has been suggested to play an important role in sperm functions; however, the cell types, pumps, and mechanisms involved have not been fully addressed. In this study, carbonic anhydrase II (CA II) and a 67-kd subunit of Neurospora crassa vacuolar proton adenosinetriphosphatase (H+ V-ATPase) pump were immunolocalized using light microscopy and electron microscopy (EM) in the epididymis of rats and mice. In both animals, narrow cells, identified in the initial segment and intermediate zone of the epididymis, contained numerous small vesicles in their apical region, often cup-shaped in appearance. In the mouse but not rat, these cells also possessed numerous cisternae of smooth endoplasmic reticulum, suggesting steroid synthesis; and cytoplasmic blebs of their apical cell surface, which appeared to detach, suggesting apocrine secretion. Anti-CA II antibody was immunocytochemically localized in the light microscope within narrow cells but not over any other cell types of the entire epididymis. Anti-H+ V-ATPase antibody was also localized in narrow cells of the initial segment and intermediate zone; as well as clear cells of the caput, corpus, and cauda regions. Using EM, gold particles for anti-CA II and H+ V-ATPase antibodies were noted in the apical region of narrow cells in relation to the numerous, small, cup-shaped vesicles. Although CA II was mainly located in the cytosol near these vesicles, H+ V-ATPase appeared on their delimiting membrane and on the apical plasma membrane of these cells. A similar distribution was noted for H+ V-ATPase in clear cells. The nature of the small vesicles of the apical region of narrow cells was examined with electron-dense fluid phase tracers that were introduced into the epididymal lumen. The tracers appeared within these vesicles and a few endosomes 1 hour after injection, suggesting that they contact the apical plasma membrane. Since these vesicles are also related to CA II and H+ V-ATPase, the data suggests that, as the site of proton production, the vesicles recycle to and from the apical cell surface, and in this way, deliver protons to the epididymal lumen for acidification. Clear cells and their expression of H+ V-ATPase may also serve in this function. In summary, both narrow and clear cells appear to be involved in luminal acidification, an activity that may be essential for sperm as they traverse and are stored in the epididymis.
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PMID:Immunolocalization of CA II and H+ V-ATPase in epithelial cells of the mouse and rat epididymis. 1081 45

Aromatase is the terminal enzyme responsible for estrogen biosynthesis; it is present in the endoplasmic reticulum membrane of steroidogenic cells in vertebrates. The aromatase gene is unique and its expression is regulated in a tissue- and more precisely, in a cell-specific manner via the alternative use of various promoters located in the first exons. The aromatase gene expression, and its transduction in a fully active protein not only in somatic cells but also in germ cells of rodent testes on one hand, and the widespread distribution of estrogen receptors (ER alpha and ER beta) in the genital tract of the male on the other hand, are clearly in favour of a physiological role for estrogens in the regulation of mammalian testicular functions. Moreover, the aromatase deficiency is associated for instance with severe bone maturation problems and sterility in mouse and man; but conversely, it is well known that estrogens in excess are responsible for the impairment of spermatogenesis. Therefore these female hormones (or the androgens/estrogens ratio) play a physiological role in the development and maintenance of male gonadal functions and seem to control especially the spermatid production (both qualitative and quantitative aspects) and epididymal sperm maturation.
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PMID:Estrogens and male reproduction. 1083 68

In BALB/c mice, two maturation-related wheat-germ-binding glycoproteins (GP-49 and GP-83) are synthesized and secreted by corpus and cauda epididymis. A co-culture technique was used to investigate these glycoproteins in principal cells of corpus epididymis and the conjugation of these molecules on caput sperm. The principal cells were recovered from corpus epididymides of 4-week-old mice and cultured in RPMI 1640 medium supplemented with 10% fetal calf serum. After culturing for 3-4 days, most cells revealed epithelial cell-specific keratins in immunofluorescent localization with monoclonal antibody. By electron microscopy, a prominent nucleolus with well-extended euchromatin was revealed in the nucleus and the cytoplasm contained multivesicular bodies, and a well-developed Golgi apparatus with endoplasmic reticulum. By SDS-PAGE, GP-83 and GP-49 were revealed in the cell extracts and cell culture supernatants after incubation with 35S-methionine. Radiolabeled binding sites were also found on the surface of caput sperm co-cultured with the principal cells for 4 h in the presence of 35S-methionine. WGA-binding glycoproteins may be synthesized and secreted by the principal cells of corpus epididymis and conjugated to caput sperm during the epididymal transit.
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PMID:Conjugation of maturation-related wheat-germ-lectin-binding proteins to caput epididymal sperm in co-cultures with corpus epididymal epithelial cells of BALB/c mouse. 1095 2

The epididymis of two species of domestic birds, the domestic fowl (Gallus domesticus), duck (Anas platyrhynchos), and of domestic and feral guinea-fowl (Numida meleagris) was studied during the three main phases of the reproductive cycle (prepuberal, sexually mature and active, and sexually mature but inactive or resting) with a view to identifying major histological and ultrastructural changes associated with and distinctive for each phase. Rete testis cells accumulated numerous variably sized lipid droplets in all birds, as well as large heterogeneous and lipofuscin-containing dense bodies in the guinea-fowl, during the resting but not in the other phases. The principal or Type III cells of the connecting and epididymal ducts exhibited profound structural changes, including, but not limited to, rarefied cytoplasm, inconspicuous and general loss of sparsely granular endoplasmic reticulum, loss of secretory vesicles in the drake, and an enhanced and conspicuous presence of lipid droplets in the guinea-fowl. The rete cells appeared to be less sensitive than the Type III cells to a reduced level or absence of lumenal androgens. These phase-dependent changes may help to prevent or minimize discrepancies in the interpretation of the normal structure of the epididymis in birds during the sexually active phase, as distinct from the other two phases and their intermediate phases.
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PMID:Cyclical reproductive changes in the non-ciliated epithelia of the epididymis of birds. 1204 47

Although fertilin is a heterodimeric complex between ADAM1 (A Disintegrin And Metalloprotease 1, fertilin alpha) and ADAM2 (fertilin beta) located on the sperm surface, two different ADAM1 isoforms, ADAM1a and ADAM1b, are present in the mouse testis. In this study, we have examined the localization of ADAM1a and ADAM1b in testicular germ cells and epididymal sperm. ADAM1a was restrictedly present within the endoplasmic reticulum of germ cells, whereas epididymal sperm contained only ADAM1b on the cell surface. The precursors of ADAM1a and ADAM1b formed a heterodimeric complex with that of ADAM2 in the endoplasmic reticulum of germ cells. The heterodimeric complex between the mature forms of ADAM1b and ADAM2 was also found on the sperm surface. These data imply the potential roles of ADAM1a and ADAM1b in spermatogenesis and fertilization, respectively.
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PMID:Differential localization of ADAM1a and ADAM1b in the endoplasmic reticulum of testicular germ cells and on the surface of epididymal sperm. 1271 16

Although evidence suggests that high intracellular calcium activity ([Ca2+]i) inhibits sperm motility, data concerning [Ca2+]i within, or slightly above, the physiological range are sparse, particularly in mammalian sperm. We investigated inhibitors of the sarcoplasmic/endoplasmic reticulum Ca-ATPase (SERCA) and the plasma membrane Ca-ATPase with the objective of increasing the intracellular calcium ion activity in human spermatozoa to study its effect on motility and other functions. Thapsigargin (20 micromol/L) increased [Ca2+]i from 140 +/- 7 nmol/L over an approximately 2-min period to reach a plateau of 530 +/- 84 nmol/L (mean +/- SEM, n = 3, p < 0.05). In sperm suspended in calcium-free medium thapsigargin increased [Ca2+]i from 13 +/- 3.3 to 35 +/- 7.5 nmol/L (p < 0.01), consistent with the release of calcium from intracellular stores. Cyclopiazonic acid (60 micromol/L) caused a transient decrease in [Ca2+]i. Quercetin, (200 micromol/L) caused a rapid increase in [Ca2+]i to 1280 +/- 90 nmol/L, after which [Ca2+]i fell quickly at first but then more slowly. Thapsigargin (20 micromol/L) caused approximately 70% of sperm to acrosome react in < or = 5 min, but once acrosome reacted, many sperm died over the next 30 min. Lower concentrations of thapsigargin caused fewer acrosome reactions but were less toxic. Both thapsigargin and quercetin caused rapid dose-dependent decreases in sperm motility. The results are consistent with high [Ca2+]i in the range observed in caput epididymal or cryopreserved spermatozoa inhibiting motility, but might be confounded by other events following the acrosome reaction.
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PMID:Effects of Ca-ATPase inhibitors on the intracellular calcium activity and motility of human spermatozoa. 1463 22

The paper presents the steroidogenic features of cultured epithelial cells of rat epididymis and their ability to synthesize steroid hormones. The cytoplasm of epididymal epithelial cells accumulated lipid droplets and contained active enzymes of steroidogenesis. Numerous mitochondria with lamellar cristae occurred near lipid droplets. Frequently, mitochondria formed a direct contact with lipid droplets and smooth endoplasmic reticulum. The hormone assay showed that the epididymal epithelial cells cultured without dihydrotestosterone synthesized and released the following steroids: dehydroepiandrosterone (DHEA), testosterone (T) and 17beta-estradiol (E). The levels of DHEA and T were very low. The concentration of E detected in media of cultured epididymal epithelial cells exceeded many times the concentration of E in control media. The cytoplasmic presence of organelles and enzymes that participated in the steroid synthesis indicated their similarity to steroidogenic cells. Epididymal epithelial cells were capable of moderate in vitro synthesis of androgens. It cannot be excluded that steroidogenesis in the cultured epididymal epithelial cells is maintained to sustain 17beta-estradiol synthesis pathways.
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PMID:Steroidogenic characteristics of in vitro cultured epididymal epithelial cells of the rat. 1466 76


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