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

The distribution of protein gene product 9.5 (PGP) and ubiquitin in the spermatozoa and epithelial cells in the different regions of the rat ductus epididymidis (proximal caput, distal caput, corpus and cauda) was studied by Western blotting analyses and electron microscopical immunogold labelling. Western blotting analyses showed that the PGP immunoreactive band was very intense in the caput and cauda epididymidis and almost irrelevant in the corpus, while the ubiquitin immunoreactive band was intense in the distal caput and cauda. No ubiquitin immunoreactive band was observed in the proximal caput and only a very weak band was seen in the corpus. The results of electron microscopical immunogold labelling varied from one epididymal region to another. The proximal caput epididymidis presented immunoreaction to PGP in the rough endoplasmic reticulum, cytosol, mitochondria and microvilli of most principal cells, and in the cytosol, rough endoplasmic reticulum and mitochondria of most basal cells. No ubiquitin immunoreaction was observed in this epididymal region. In the distal caput epididymidis, PGP immunoreactivity was detected in some principal and basal cells in the same intracellular locations as described in the proximal caput. In this region, ubiquitin immunoreactivity appears in the apical cytosol and mitochondria of principal cells. The corpus epididymidis showed no immunoreaction to PGP or ubiquitin. In the cauda epididymidis, immunostaining to PGP was observed in most clear cells and in isolated principal cells. The intracellular location of PGP in both cell types was the cytosol, mitochondria and microvilli. Ubiquitin immunoreactivity was detected in the perinuclear cytosol and mitochondria-but not in the digestive vacuoles-of some clear cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ultrastructural localization of PGP 9.5 and ubiquitin immunoreactivities in rat ductus epididymidis epithelium. 755 92

The aim of the present study was to provide a comprehensive morphological analysis of the porcine epididymis in view of the specific functions being performed in different regions of this organ. Blood supply and microvasculature of efferent ductules and epididymal duct were investigated by means of corrosion casts which were analysed macroscopically and by scanning electron microscopy. This revealed blood supply to the testis and epididymis to be closely related. The capillary pattern was typical for the efferent ductules, the caput, corpus, and distal cauda epididymidis, respectively. Corrosion casts were also used to visualize the course of the efferent ductules themselves. Tissue samples from different regions of the efferent ductules and epididymal duct were examined by light microscopy and both scanning and transmission electron microscopy, with special attention being payed to transitional areas. Morphological criteria allowed the distinction of three segments within the efferent ductules and of the initial segment, proximal caput, distal caput, corpus, proximal cauda, and distal cauda regions of the epididymal duct. Components of the endocytic apparatus of efferent ductule principal cells were identified by ferritin uptake. Ultrastructural evidence of absorption in the epididymal duct was particularly prominent in proximal and distal caput. Extensive cisternae of rough endoplasmic reticulum and a well-developed Golgi apparatus were indicative of active protein synthesis and secretion especially in the distal caput and corpus regions. However, assignment of various organelles in principal cells of the epididymal duct to either absorptive or secretory pathways still remains tentative.
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PMID:Morphological characteristics of boar efferent ductules and epididymal duct. 787 92

Very little is known about the basal cells in the epididymal epithelium. Their function is unclear, although they are present in all mammalian epididymides studied. The corpus epididymides from five patients undergoing castration because of prostatic carcinoma were fixed and processed for electron microscopy. Basal cells were characterized by a slightly heterochromatic nucleus with prominent nucleolus, pale round mitochondria, dispersed endoplasmic reticulum, and sparse Golgi apparatus; they were often rich in lipofuscin inclusions, possibly originating from principal cells. Some peritubular macrophages in close proximity to the epithelium were structurally similar to basal cells. Immunohistochemical staining revealed in the epididymides of another ten patients that the basal cells were recognized by the monoclonal antibody (mAb) 25F9 against mature, tissue-fixed macrophages but not by mAbs 27E10 or RM3/1, which were against activated macrophages usually found in acute or late inflammation, respectively. On the basis of the present findings, as a working hypothesis a scavenging role of the basal cells in a local immune defense mechanism is proposed, in which antigenic products (possibly of sperm degradation), taken up by the principal cells, would be phagocytosed by the basal cells. It could be inferred that when the basal cells are overloaded, they would leave the epithelium to be replenished by tissue-fixed macrophages.
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PMID:Basal cells of the human epididymis--antigenic and ultrastructural similarities to tissue-fixed macrophages. 819 71

The response of the male reproductive tract to vasectomy includes inflammation of the interstitial tissue of the epididymis. The pathogenesis of epididymal interstitial reactions and characteristics of the responding cells were studied by electron microscopy in Lewis rats at intervals following bilateral vasectomy, vasectomy followed 1 month later by vasovasostomy, or sham operations. In areas of interstitial reaction, numerous macrophages, monocytes, lymphocytes, neutrophils, and plasma cells occupied the connective tissue. Macrophages, containing many lysosomes and vesicles, aggregated and assumed the appearance of epithelioid cells. Processes of adjacent macrophages interdigitated with one another and closely approached the surfaces of lymphocytes. Many plasma cells with distended rough endoplasmic reticulum appeared in the interstitium. The majority of animals in the vasectomy and vasovasostomy groups exhibited epididymal interstitial changes by 2-3 months; the cauda epididymidis was the region most often affected. The ultrastructural features were indicative of chronic granulomatous inflammation and were consistent with an immune response that includes antigen presentation by macrophages to lymphocytes, lymphocyte differentiation, and local antibody production by plasma cells. The nearly complete absence of sperm or recognizable parts thereof in the interstitial tissue in the areas of the reactions suggests that these lesions formed in response to soluble antigens leaking from the duct. Vasovasostomy was not effective in reversing or retarding epididymal inflammation at the intervals studied.
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PMID:Ultrastructure of epididymal interstitial reactions following vasectomy and vasovasostomy. 841 29

Caltrins, the small, basic proteins of the seminal vesicle secretion that inhibit calcium transport into epididymal spermatozoa, and consequently the onset of the acrosome reaction and the hyperactivated motility, were localized in the epithelial cells and the lumen of the seminal vesicles of the guinea pig by an immunocytochemical procedure and electron microscopy. Rabbit antisera against each protein (caltrin I or II), and goat anti-rabbit IgG antiserum labeled with colloidal gold were used to detect the caltrin immunoreaction. The subcellular distribution of the gold labeling was occasionally localized in the rough endoplasmic reticulum but mainly within big secretory vacuoles containing low electron-dense material, which are components of the Golgi complex known as condensing vacuoles. These are involved in the intracellular transport, storage, and discharge of secretory proteins. Gold-labeled material released to the lumen was also detected. There was no clear evidence that the discharge was mediated by an exocytotic process. Immunoreaction was observed neither in the electron-dense core nor in the electron-lucent halo of the typical secretory granules of the epithelial cells of the seminal vesicles. Using light microscope immunocytochemistry, intense positive immunoreactivity was detected in the material secreted to the lumen but not on the epithelial cell layer. Only those cells undergoing a degenerative process and showing a picnotic nucleus and condensed cytoplasmic matrix exhibited detectable immunoreaction when gold label and silver intensification were applied. The same distribution of the immunoprobes was obtained by electron or light microscopy when antiserum to either I or II was used. It would appear that the two caltrin proteins of the guinea pig are synthesized in the rough endoplasmic reticulum of the epithelial cells and transported quickly to the Golgi complex where the secretory vacuoles (condensing vacuoles) are formed. The proteins are transported by the secretory vacuoles to the apical ends of the cells to be discharged into the lumen.
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PMID:Electron microscopic immunolocalization of caltrin proteins in guinea pig seminal vesicles. 858 79

The maturation of spermatozoa in the epididymis is a complex process that requires the active involvement of the epididymal epithelium. The primary focus toward elucidating the role of the epididymis in the maturation process has been the study of epididymal secretory proteins and their interaction with spermatozoa. To date there is a paucity of information regarding epididymal epithelial cell surface proteins, which may also play important roles in epididymal function. Through a subtractive hybridization approach to identify genes specifically expressed in the caput epididymidis, the mouse homologue of a member of the ADAM (a disintegrin and metalloprotease) family of proteins was identified. This rapidly growing gene family encodes cell surface proteins that possess putative adhesion and protease domains. Northern blot analyses demonstrated that the mouse ADAM gene, termed ADAM7, is expressed in the caput region of the epididymis and in the anterior pituitary gonadotropes with no detectable expression in the twenty-six other tissues examined. Furthermore, in situ hybridization experiments revealed that the ADAM7 messenger RNA (mRNA) exhibited an apical localization within the proximal caput epididymal epithelium that may correlate with an unusual sparsely granulated endoplasmic reticulum uniquely present in the proximal region of the epididymidis and to which no known function has been ascribed. Hormonal, surgical, and genetic strategies demonstrated that ADAM7 gene expression requires, in a region-dependent manner, androgens as well as testicular factors for expression. Interestingly, the apical localization of ADAM7 mRNA is dependent upon an intact testis, because in situ hybridization analyses of the proximal caput epididymidis from a testosterone maintained castrate mouse did not show the apical localization of ADAM7 mRNA. Finally, chromosomal mapping demonstrated that the ADAM7 gene maps to the central region of mouse Chromosome 14, approximately 4-5 cM distal from the fertilin beta locus, which encodes another reproductive-specific ADAM protein.
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PMID:ADAM7, a member of the ADAM (a disintegrin and metalloprotease) gene family is specifically expressed in the mouse anterior pituitary and epididymis. 932 39

The expression and androgen regulation of egasyn, the endoplasmic reticulum-targeting protein of beta-D-glucuronidase, was examined in the mouse-epididymis. The proximal (caput) and distal (corpus & cauda) epididymal tissue extracts were prepared by homogenization and sonication in buffered Triton X-100 solution, and high speed centrifugation. The supernatant when resolved by 2D-PAGE under non-denaturing conditions and stained for esterase activity showed that the distal (but not proximal) epididymis of the normal mouse contain several specific forms of esterases. These forms include a series of four variants (pI 5.2-5.75) with high mobility (HM) and esterase activity, and three faintly staining variants (beginning at pI 6.0) with low mobility (LM). Several lines of evidence indicate that the specific esterases seen in the corpus/cauda epididymidis are egasyn-esterases. Firstly, these molecular forms were not seen in the distal epididymal extracts from the egasyn-deficient mouse. Secondly, the HM forms can be immunoprecipitated with anti-egasyn antibody, suggesting the presence of free egasyn. Finally, the LM forms disappeared after heat treatment (56 degrees C for 8 min), a condition known to dissociate egasyn:beta-D-glucuronidase complex. This result indicates that a small amount of egasyn is complexed with beta-D-glucuronidase. Immunoblotting (Western blot) studies (using anti-egasyn antibody) following resolution of egasyn released from the egasyn:beta-D-glucuronidase complex revealed a single band of an apparent molecular weight 64 kDa in the distal (but not proximal) epididymis, indicating that the mouse epididymal egasyn is identical or very similar to the liver egasyn. Castration of mice lead to the appearance of free and complexed egasyn forms in the proximal epididymis. Testosterone supplementation to the castrated mice resulted in the disappearance of the induced egasyn forms from the caput epididymidis. Taken together, these results indicate that the expression of egasyn in the epididymis is region-specific and is differentially regulated by androgens.
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PMID:Identification and androgen regulation of egasyn in the mouse epididymis. 953 73

The Golgi apparatus of epididymal principal cells shares many structural features with other cell types. Saccular regions are arranged in a cis-Golgi network, eight flattened saccules, and several trans-Golgi networks (TGNs). Dilated tubules form intersaccular connecting regions which joint together saccules at the same or different levels between adjacent stacks. Wells exist as large perforations in register with the four cis-most saccules and serve as areas of vesicular interactions. TGNs are variable and can appear to peel off the stack or to be detached from it in the form of an anastomotic tubular network with pale dilated areas corresponding to prosecretory granules connected by short narrow bridges. Elongated or discoid dilated cisternae of endoplasmic reticulum (ER) (sparsely granulated) lie over the cis face of the stack, from which they are separated by an intermediate compartment filled with vesicles and tubules. The ER is also closely juxtaposed to the TGNs and the eighth saccule but interconnections are never seen between them. Vesicles of the COP variety reside at all levels of the stack and appear to bud off the cis-located ER and the edges of the saccules, while clathrin-coated vesicles appear mainly on the trans face of the stack and next to lysosomes. In the supranuclear cytoplasm, clusters of vesicles and tubules, at times budding off enveloping ER, appear to radiate toward the Golgi stacks where they fuse with cis Golgi elements. Taken together, these observations suggest dynamic functions and interactions for the various Golgi elements, associated vesicles, ER, and vesicular tubular clusters.
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PMID:The structure of the Golgi apparatus: a sperm's eye view in principal epithelial cells of the rat epididymis. 968 26

Unidentified tubulovesicular profiles have been reported in the apical cytoplasm of boar caput epididymal principal cells in addition to vesicles considered to be involved in endocytosis and secretion. The main aim of the present study was to clarify the character of these organelles and to differentiate them from the endocytic apparatus. Glucose-6-phosphatase (G6Pase) activity was determined as the reporter enzyme of the endoplasmic reticulum (ER) and phosphotungstic acid was used to visualize carbohydrate moieties in both the proximal and distal caput. Phosphotungstic acid revealed the glycocalyx of the endocytic apparatus, which was similar in both regions studied, and also stained specific granules of the proximal caput. Glucose-6-phosphatase showed the tubulovesicular profiles to be sparsely granulated ER that was poorly developed in the proximal caput and very abundant in the apical cytoplasm of the distal caput principal cells. The function of such large amounts of sparsely granulated ER with corresponding G6Pase activity in caput epididymal principal cells is unknown.
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PMID:Localization of glucose-6-phosphatase activity and carbohydrates in boar caput epididymal principal cells. 987 61

Spermatozoa released from the seminiferous tubules are terminally differentiated cells with no known synthetic activity. Their components are synthesized in the spermatogenic cells during spermatogenesis. In this study, we report the characterization and immunolocalization of beta-glucuronidase in mouse testicular germ cells and spermatozoa. The enzyme is an exoglycohydrolase with dual localization, being present in lysosomes and endoplasmic reticulum of several mouse and rat tissues. The purified germ cell preparations (spermatocytes, round spermatids, and condensed/elongated spermatids) when assayed for beta-glucuronidase activity showed that the spermatocytes contained five times more enzyme activity per cell than the spermatids. Polyacrylamide gel electrophoresis, carried out under native and denaturing conditions, demonstrated that the germ cells express only the lysosomal form of the enzyme (pI 5.5-6.0) with a subunit molecular mass of 74 kDa. Immunocytochemical studies revealed a positive reaction in the Golgi membranes, Golgi-associated vesicles, and lysosomes of late spermatocytes (pachytene spermatocytes) and a stage-specific localization during spermiogenesis. The forming or formed acrosome of the elongated spermatids (stages 9-16) and epididymal spermatozoa was highly immunopositive. Comparison of immunoprecipitation curves and kinetic properties of the enzyme present in spermatocytes and spermatozoa revealed no major differences. Taken together, our results demonstrate that beta-glucuronidase activities present in the lysosomes of spermatocytes and the sperm acrosome are kinetically and immunologically similar.
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PMID:Characterization and immunolocalization of beta-D-glucuronidase in mouse testicular germ cells and spermatozoa. 1004 47


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