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

A well-developed Golgi apparatus and rough and smooth endoplasmic reticulum in the principal cells of the mouse epididymis indicate active protein synthesis. Studies have shown that epididymal secretions are essential for sperm maturation. In a previous study, two wheat-germ agglutinin (WGA)-binding glycoproteins, GP-49 and GP-83, were identified on the surface of mature mouse sperm. In this study, synthesis and secretion of these two glycoproteins were investigated. Apparent WGA-binding was found on the stereocilia and in the apical region of principal cells in the corpus and cauda of epididymis. Post-fixation and pre-embedding cytochemical localization revealed that WGA-binding sites were situated in the Golgi apparatus, multivesicular bodies and stereocilia of principal cells. GP-49 and GP-83 were identified in the Nonidet P-40 homogenates of corpus and cauda epididymidis. In the epididymides of which ductuli efferentes had been ligated for more than 4 weeks, no sperm were found in the lumina of epididymal tubules. WGA-binding sites were present in the corpus and cauda; GP-49 and GP-83 were identified in tissue homogenates of the corpus and cauda as well. These findings suggest that GP-49 and GP-83 of mature sperm may be secreted by the principal cells of the corpus and cauda. These two molecules apparently conjugate to sperm whilst sperm transit through the epididymis.
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PMID:The secretion of two sperm maturation-related glycoproteins in BALB/c mouse epididymis. 178 90

We used antibodies that specifically bind annexins on Western blots to determine the distribution and abundance of these proteins in ram spermatids and sperm by immunogold electron microscopy. Annexins I and II were found essentially within the entire acrosome of spermatids. During epididymal maturation, they concentrated in the postacrosomal region or the acrosomal equatorial segment, respectively. They were also present in sperm flagellum, on the surface of the coarse fibers and fibrous sheath. These findings show that during ram germ cell maturation, annexins I and II are exported from the spermatid acrosome towards structurally and functionally defined parts of the sperm. Annexins III, IV, and V were not found in ram germ cells. Annexin VI was isolated from testis and sperm. In spermatids, it was found to be associated with endoplasmic reticulum and the mitochondria but was absent from the acrosome. In sperm, it was confined to the flagellum, the mitochondria, and on the coarse fibers and fibrous sheath. The presence of three annexins, in addition to calmodulin, in functional areas may indicate differential ways for sperm to control and regulate events that are known to be calcium dependent, such as flagellar motility, acrosome reaction, and fertilization.
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PMID:Differential localization of annexins in ram germ cells: a biochemical and immunocytochemical study. 183 Aug 93

Ultrastructural changes in the epididymal epithelium and the fate of accumulating spermatozoa were examined in the vasectomized rhesus monkey (Macaca mulatta). Accumulation of spermatozoa resulted in an increase in the diameter of the tubule and its lumen. Ultrastructure of principal cells revealed that they continue to perform both secretory and absorptive functions after vasectomy. The rough endoplasmic reticulum, Golgi complex, and mitochondria were well developed in the principal cell. Bulging of the apical portion of principal cells and membrane-bound structures in the lumen suggests an increase in apocrine secretion. An increase in the number of vesicles, vacuoles, and multivesicular bodies in the principal cells indicates an increased absorptive activity. Increased absorptive function was also evident in the apical cells. Macrophages with sperm remnants were seen in the lumen, and occasionally in the connective tissue. The principal or only mechanism of sperm disposal after vasectomy appeared to be intraluminal endocytosis by macrophages.
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PMID:Effect of vasectomy on the ultrastructure of epididymal epithelium in rhesus monkey. 197 25

Histologic changes in the mouse epididymides were examined by light and electron microscopy 1, 3, 6 and 10 weeks after surgical fixation of the testes and epididymides to the internal abdominal wall at 2 months of age. In the epididymides subjected to the cryptorchid surgery, the principal cells in the segment next to the initial segment became taller, the nuclei were translocated to a higher position, and the widened infranuclear cytoplasm turned pale. The supranuclear cytoplasm showed a decrease in PAS stainability. Electron microscopy revealed that the infranuclear cytoplasm, which is occupied by small vesicular endoplasmic reticulum in the normal cells, was filled with distended rough endoplasmic reticulum. These changes first appeared one week after operation, further developing with time. Similar changes were observed when the epididymis was in the abdominal position with the testis in the scrotal position, or with the efferent duct ligated to block the testicular fluid flow into the epididymis. It is suggested that the epididymal changes recorded in this paper are induced by the elevation of temperature caused by the translocation from the scrotum to the abdomen.
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PMID:Histologic changes in the mouse epididymis fixed in the abdominal cavity. 219 19

The ultrastructure of the principal cells of the mouse epididymis was studied using osmium impregnation techniques which have the advantage that the endoplasmic reticulum (ER) content displays a positive reactivity after glutaraldehyde fixation whereas the Golgi condensing vacuoles are negative. In the proximal part (caput) of the epididymis, the Golgi apparatus formed a large supranuclear area filled with electronluscent secretory vacuoles while, in the medial (corpus) and distal (cauda) parts, dictyosomes were small and sparse with few secretory vacuoles. In all the principal cells of the caput, the supranuclear ER cisternae were heterogeneously impregnated. In the corpus and cauda, the ER appeared as an extensive continuous network of canaliculi and saccules which were fenestrated when surrounding mitochondria. The ER content was homogeneously stained but impregnation intensity varied from cell to cell. In the apex of the caput cells, numerous impregnated or electronluscent vesicles were seen in close apposition to the plasma membrane, while in the corpus and cauda some Golgi vacuoles and extensions of ER canaliculi were observed in the terminal webb region. Thus, in the epididymal caput, osmium impregnation suggested that two distinct secretory pathways were functioning continuously. The first corresponded to the transport of proteins to the cell membrane by the Golgi condensing vacuoles. The second might only affect the small impregnated vesicles of the ER, through which proteins bypassed the Golgi apparatus and were exported towards the lumen. In the corpus and cauda, the network organization of the ER and the association of fenestrated cisternae with mitochondria (also found in absorptive epithelial cells) supported the view of a predominant absorptive function in these epididymal parts.
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PMID:Organization of the internal membrane system in the principal cells of the mouse epididymis after osmium impregnation. 247 97

The aim of the performed studies has been to find out wether or not the ultrastructural alterations of the epithelial cells in the rat's epididymal caput occur in hyperprolactinemia induced by metoclopramide and to see if the observed changes are of reversible character. It has been revealed that prolactin concentration was twice as high as in control animals due to peritoneal administration of metoclopramide in a dose of 2.2 mg/kg body mass, given for 14 days. The ultrastructural alterations in the principal cells of epididymal caput affected cellular organelles being involved in proteins synthesis, glycosylation, secretion as well as energetic processes. They were manifested by decreased amount of rough endoplasmic reticulum, widening of its cisternae combined with degranulation, distension of Golgi apparatus cisternae, elevated number of vesicles in apical part of the cells, and changes in mitochondria. The termination of metoclopramide administration made prolactin concentration exhibit values being almost similar to those determined in control rats, whereas the ultrastructural changes in the principal cells were found to be reversible.
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PMID:Ultrastructure of epithelial cells in rat's epididymal caput in experimental hyperprolactinemia induced by metoclopramide. 263 74

The present study was conducted to provide biochemical and morphological evidence for ethanol-induced impairment of testicular development. The specific activities of testicular postmeiotic enzyme markers--sorbitol dehydrogenase (SDH), lactate dehydrogenase (LDH), and alpha-glycerophosphate dehydrogenase (GDH)--increased with age in CFW mice from ages 23 to 60 days, providing a biochemical measure of testicular development during puberty. Chronic ethanol treatment via liquid diets from ages 20 to 55 days resulted in decreased activities of SDH and LDH at ages 40 and 44 days, and of GDH at ages 34, 40, and 44 days. These decreases were consistent with an arrest in the developmental increase in SDH, LDH, and GDH at ages 31 +/- 0.6, 31 +/- 2.6, and 24 +/- 0.5 days, respectively. After 29 days of ethanol treatment (age 50 days), testicular weights, epididymal sperm content, and sperm motility were reduced, relative to controls, by 37, 83, and 60%, respectively (p less than 0.05). Epididymal weights were unaffected. Light microscopic evaluation of testes revealed disorganization of spermatogenesis, germ cell degeneration, decreased tubular luminal diameter, and vacuolation of Sertoli cells in ethanol-treated mice at age 50 days. Electron microscopic analysis showed that germ cell degeneration was not restricted to a specific cell type. Stage IX-XI tubules were observed in which spermatids had been retained and underwent phagocytosis within the Sertoli cell. Sertoli cells showed evidence of atypical nuclear invaginations. Sertoli cells underwent degenerative changes and were sloughed into the rete testis. However, relative Leydig cell size, as well as fractional volume occupied by the nucleus, mitochondria, and endoplasmic reticulum were unaffected by ethanol. The data (1) confirm previous findings suggesting ethanol-induced delayed testicular development; (2) suggest that certain aspects of testicular development are arrested relatively early in ethanol treatment (4-11 days); and (3) indicate that the Sertoli cell, rather than the Leydig cell, is the primary target with regard to the deleterious effect of chronic ethanol treatment on testicular maturation.
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PMID:Biochemical and structural evidence for ethanol-induced impairment of testicular development: apparent lack of Leydig cell involvement. 276 3

Upon release from the seminiferous epithelium, spermatoza show a small droplet of cytoplasm attached to the neck region. During transit of spermatozoa in the caput epididymidis, this cytoplasmic droplet migrates along the middle piece of the flagellum. In the corpus epididymidis, the droplet shows a lateral displacement, while in the cauda epididymidis it detaches from the spermatozoon. In the electron microscope, cytoplasmic droplets attached to spermatozoa were seen to contain numerous, short, straight or C-shaped, flattened membranous elements referred to as lamellae, small vesicles, and small particles (35-nm diameter) with a diffuse wall showing no apparent unit membrane. The lamellae were stacked closely on one another or arranged in a loose array. Structurally as well as cytochemically, with different cytochemical markers, the lamellae and vesicular elements failed to show any evidence of being components of the Golgi apparatus or elements of the endoplasmic reticulum. The lamellae, vesicular elements, and 35-nm particles were also seen free in the lumen of the corpus epididymidis but were especially prominent in the cauda epididymidis at a time when droplets were being released from spermatozoa. The lumen of the epididymis, as spermatozoa passed from the caput to the cauda epididymidis, was also noted to acquire progressively a flocculent background material. The epididymal epithelium is composed predominantly of principal and clear cells. The endocytic activity of clear cells was examined in rats at different time intervals after a single injection of cationic ferritin into the lumen of the cauda epididymidis. At 2 min the tracer was bound to the microvilli of these cells and was also observed within large coated and uncoated pits, subsurface coated vesicles, and numerous subsurface small uncoated vesicular membranous elements (150-200-nm diameter). At 5 min, in addition to the above structures, the tracer was present in endosomes, while at 15 and 30 min, pale and dense multivesicular bodies appeared labeled, respectively. At 1 and 2 hr, but more so at 6 hr large dense membrane-bound bodies identified cytochemically as secondary lysosomes became labeled. All of the above endocytic structures were also seen to contain the 35-nm particles, flattened or vesicular membranous profiles, and a fine flocculent background material reminiscent of those seen free in the lumen or found in cytoplasmic droplets attached to spermatozoa. (ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Role of epithelial clear cells of the rat epididymis in the disposal of the contents of cytoplasmic droplets detached from spermatozoa. 284 96

The differentiation of the rat epididymis was studied in prepubertal castrated, ligated or cryptorchid rats, in order to assess the influences of blood-borne and luminal androgens. The principal cells showed partial differentiation: decrease in cell height, decreased numbers of cytoplasmic organelles implicated in the elaboration phenomena (Golgi apparatus, smooth endoplasmic reticulum), whereas the organelles implicated in the absorptive function remained relatively intact. The lamina densa of the basement membrane underlying the epithelium was irregular, thicker than normal and followed the irregular outline of the basal parts of the epithelial cells. These changes were evident in castrated rats, to a lesser degree in ligated and cryptorchid rats, and were more prominent in the initial part of the duct. On the other hand, the narrow cells and the clear cells followed a normal differentiation pattern in the experimental rats, suggesting that a differential androgen dependence exists among the various type of epididymal cells.
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PMID:Influence of testicular secretions on differentiation in the rat epididymis: ultrastructural studies after castration, efferent duct ligation and cryptorchidism. 288 75

Antagglutinin, a specific protein synthesized by the boar epididymis, was secreted by the principal cells of the initial segment, the caput and the corpus, but was not detectable in the caudal cells. Castration completely abolished the synthesis and secretion of antagglutinin in all epididymal cells. Androgen replacement suggests that the epithelial cells from different segments have differential regulatory mechanisms. The proximal zone appeared refractory to exogenous testosterone; the median zone was a typical androgen-dependent region; and the caudal cells, where an unusual secretion of antagglutinin was detected, revealed still a different reaction pattern. It is postulated that these latter cells depend not solely on androgen but also or exclusively on other factors. Our results, which demonstrate a primary role of the Golgi complex in the secretory process in the epididymal cells, also suggest that the apical smooth endoplasmic reticulum may be implicated in the intracellular transport of glycoproteins to the cell surface.
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PMID:Androgenic control of antagglutinin secretion in the boar epididymal epithelium. An immunocytochemical study. 292 38


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