Different Regions Of Epididymis Research Articles

Extracellular vesicles are involved in the paracrine communication between epithelial cells in different regions of the domestic cat epididymis.

Sperm maturation depends on exposure to specific microenvironments within the different segments of the epididymis, but mechanisms underlying how these microenvironments are produced or maintained are not well understood. We hypothesized that epididymal extracellular vesicles (EVs) could play a role in the process of maintaining microenvironments in different regions of the epididymis. Specifically, we tested whether the EVs from different regions of the epididymis can serve as a form of paracrine communication between cells in different segments. Domestic cat tissues were used to develop a reproducible in vitro culture system for corpus epididymis explants that were then exposed to EVs collected from upstream (i.e. caput) segments. The impacts of different culture or exposure conditions were compared by analyzing the morphology, apoptosis, transcriptional activity, and gene expression in the explants. Here, we report the development of the first in vitro culture system for epididymal tissue explants in the domestic cat model. Using this system, we found that EVs from the caput segment have a significant effect on the transcriptional profile of tissue from the corpus segment (1233 differentially expressed genes due to EV supplementation). Of note, expression of genes associated with regulation of epithelial cell differentiation and cytokine signaling in the epididymis were regulated by the presence of EVs. Together, our findings comprise the first report of paracrine control of segmental gene regulation by epididymal EVs in any species. These results contribute to a better understanding of epididymis biology and could lead to techniques to enhance or suppress male fertility.

Analysis of histomorphology and SERNINA5 gene expression in different regions of epididymis of cattleyak.

The molecular mechanism of sterility in cattleyak is still unresolved. The related factors of infertility in cattleyak were studied by tissue section, SERPINA5 gene cloning and bioinformatics technology. Tissue sections of the epididymis showed poorly structured and disorganized epithelial cells in the corpus of the epididymis compared to the caput of the epididymis, while in the cauda part of the epididymis, the extra basal smooth muscle was thinner, the surface of the epithelial lumen was discontinuous and the epithelium was markedly degenerated. The results of gene cloning showed that the coding sequence (CDS) region of the SERPINA5 gene in cattleyak was 1215bp in length, encoding a total of 404 amino acids, of which the isoleucine content was the highest, accounting for a total of 49 amino acids (12.1%). The results of real-time fluorescence quantitative PCR (qPCR) showed that the expression of the SERPINA5 gene in the epididymis caput in cattleyak was significantly higher than that in the corpus and cauda (P < 0.05), but there were no significant differences between the corpus and cauda. In the current study, histological and bioinformatics analysis, physicochemical properties, and the expression analysis of the SERPINA5 gene in different regions of the epididymis in cattleyak were carried out to explore the biological complications of cattleyak infertility.

Differential Distribution of GABA and GAT1 in Mouse Epididymis

The present study is to explore the relationship between GABA/GAT1 and mechanism of sperm maturation in epididymis. The distribution of GABA and GAT1 was observed under microscope in different magnifications. Immune labeled GABA and GAT1 at the different regions of epididymis was semi-quantified. Our data illustrated that GABA was significantly higher produced at caput of epididymis than that at corpus or cauda of epididymis. Consistently, the distribution of GAT1 showed similar patterns at the different regions of epididymis. The current data suggested that differential expression of GABA and its transport protein I (GAT1) at the different regions of epididymis may be related to maturation and subsequently the function of sperms. Such information may also contribute to our clinical practice in Andrology.

Interaction Between Smad1 and p97/VCP in Rat Testis and Epididymis During the Postnatal Development

Members of the bone morphogenetic proteins (BMPs) superfamily are expressed in the testis and epididymis and are believed to have different biological functions during testicular and epididymal development. Smad1 is one of the signal transducers of BMP signaling and binds to several proteins involved in ubiquitin-proteasome system (UPS). Valosin-containing protein (p97/VCP) is required for the degradation of some UPS substrates. Although p97/VCP has been indicated in different cellular pathways, its association with BMP signaling in male reproductive system has not been elucidated. The aim of the present study was to investigate the cellular localization of Smad1, phospho-Smad1, and p97/VCP and the interaction of proteins in the postnatal rat testis and epididymis. Testicular and epididymal tissues from 5-, 15- and 60-day-old rats were examined by immunohistochemistry, immunofluorescence, Western blotting, and immunoprecipitation techniques. In 5-day-old rat testis, Smad1, phospho-Smad1, and p97/VCP were mainly expressed in gonocytes. In 15- and 60-day-old rat testis, proteins were overlapped in spermatogonia, Sertoli cells, and spermatocytes. Expression of proteins in the epithelial cells of epididymis was gradually increased from 5 to 15 days of age. Smad1 and phospho-Smad1 expressions showed uniformity in the different regions of epididymis, however p97/VCP immunoreactivity was higher only in caput epididymis compared to corpus and cauda epididymis in 15- and 60-day-old rat epididymis. Co-immunoprecipitation experiments further confirmed the Smad1-p97/VCP and p-Smad1-p97/VCP interactions. The overlap between Smad1 and p97/VCP expressions in the postnatal rat testis and epididymis suggests that p97/VCP may play important roles in mediating BMP signaling during spermatogenesis.

Histological and immunohistochemical studies on the epididymal duct in the dromedary camel (Camelus dromedarius)

This study was conducted to underscore the spatial distribution of some biologically active proteins within the epididymal duct in the dromedary camel. Paraffin-embedded sections from different regions of epididymis were stained by conventional histological techniques and by immunohistochemistry. A battery of primary antibodies against six proteins (S100, alpha smooth muscle actin [α-SMA], connexin-43 [Cx43], galactosyltransferase [GalTase], angiotensin converting enzyme [ACE], and vascular endothelial growth factor [VEGF]) were used. The epididymal epithelium consisted of five cell populations: principal, basal, apical, dark, and halo cells. The histochemical findings indicated the absence of binding sites for VEGF and Cx43. The principal cells (PCs) showed variable immunoreactivity (IR) for ACE, S100, and GalTase throughout the whole length of the duct. The apical surfaces of most PCs (at the caput) and some PCs (at the corpus) exhibited intense ACE-IR, whereas those at the cauda displayed alternating negative and strong immunostaining. Similarly, moderate S100-IR was found in cytoplasm and nuclei of all PCs at the caput, few PCs at the corpus, and several PCs alternating with negative PCs at the cauda. In contrast, only some PCs showed weak to strong GalTase-IR in different regions. Apart from negative to weak positive S100-IR, basal cells failed to show IR for all other proteins. Apical cells displayed strong IR for ACE, S100, and GalTase with some regional differences. The peritubular and vascular smooth muscle cells revealed strong α-SMA-IR in all regions. In conclusion, the spatial distribution of different proteins in camel epididymis showed similarities and differences to other mammalian species. The region-specific topographic distribution of different proteins and cell types might indicate that the caput and cauda are metabolically more active than that of the corpus.

Expression of Occludin in Testis and Epididymis of Wild Rabbits,Lepus sinensis coreanus

Tight junctions (TJs) in inter-Sertoli junctional areas and epididymal epithelia build up the blood-testis barrier (BTB) and the blood-epididymal barrier (BEB), respectively. In this study, the expression of occludin, an integral member of the TJs, was examined in testis and different regions of epididymis of Lepus sinensis coreanus, an Korean wild rabbit species. In testis, intense occludin immunoreactivity was found in the basally located inter-Sertoli junctional area together with diffused immunoreactivity of occludin in the cytoplasm of Sertoli cells. It can be suggested that occludin is one of the robust elements of BTB in seminiferous tubules of rabbit testis. In proximal and distal caput epididymis, occludin immunoreactivity was found in the lateral as well as apical contacts of epithelial cells. In corpus epididymis, intense occludin immunoreactivity was found in the basolateral as well as apical contacts of epithelial cells together with cytoplasmic signal. In cauda epididymis, occludin immunoreactivity in luminal epithelia was relatively strong but largely found in the cytoplasm. This suggests that intriguing regulatory mechanisms differentially recruit occludin to the TJ in the different regions of epididymal epithelia. The differences in the subcellular localization as well as expression levels of occludin among the epididymal segments may reflect differential paracellular permeability of epithelia along the epididymal tubules and be correlated with sperm maturation in rabbit. In Western blot, a major form of occludin was MW 62 kDa together with small fragments of MW 34-39 kDa in testis and epididymis, suggesting the peptide cleavage of occludin. This is the first report on the molecular nature of TJs in a wild rabbit testis and epididymis.

Aquaporin 9 (AQP9) Localization in the Adult Dog Testis Excurrent Ducts by Immunohistochemistry

Aquaporins (AQPs) are small, intrinsic membrane proteins that are present in many cell types involved in fluid transport. AQP9 is a major apical water channel that is expressed throughout the efferent ducts, epididymis, and vas deferens, as well as in other regions of the human and rodent male reproductive tract. The target of this study was to examine the expression of AQP9 in epithelial cells in the adult dog efferent ducts, epididymis, and vas deferens. Samples of dog male reproductive tract comprising fragments of the testis; initial segment, caput, corpus, and cauda of the epididymis; and vas deferens were obtained from eight adult mongrel dogs. Immunohistochemistry and Western blotting procedures were used to show AQP9 localization and distribution. AQP9 expression was not detected either in dog seminiferous tubules or rete testis. However, apical labeling for AQP9 was detected in the different regions of epididymis and vas deferens, with the reaction being less intense in the caput epididymis. Thus, AQP9 is abundantly expressed in dog male reproductive tract, in which it is an important apical pathway for transmembrane flow of water and neutral solutes.

Obstructive infertility: changes in the histology of different regions of the epididymis and morphology of spermatozoa

In the present study, the effects of prolonged obstruction in different regions of the human epididymis on its histology and on the spermatozoa retained at the site of obstruction were assessed. Men who were confirmed of having obstruction of the epididymis underwent vasoepididymostomy (VEA) for surgical correction of the obstruction. At the time of surgery, fluid from the epididymal tubule above the site of obstruction was aspirated and examined for sperm profile. Epididymal tissue, collected at the site of obstruction, was processed for assessment of histological changes and also used to identify the site of obstruction. Prolonged obstruction of the epididymis has caused degeneration of the epididymal epithelium, gradual decrease in the diameter of the tubule and tubular lumen and increase in the intertubular connective tissue. Sperm aspirated from the caput epididymal fluid showed sluggish pattern of motility only in one out of the six subjects, whereas spermatozoa collected from the cauda epididymal fluid showed rapid linear progressive motility in one of three subjects. A major percentage of spermatozoa in the aspirated fluid showed various types of morphological abnormalities, irrespective of the site of obstruction. These results are discussed in relation to the role of the epididymis in investing spermatozoa with motility and fertilizing capacity.

Stage and region-specific localization of lipocalin-type prostaglandin D synthase in the adult murine testis and epididymis.

Lipocalin-type prostaglandin D synthase in semen has been associated with male fertility, although this relationship is not well defined. To gain insight into potential mechanisms, the objective of the present study was to immunocytochemically localize lipocalin-type prostaglandin D synthase within the testis, efferent ducts, and 4 segments of mouse epididymis. In the testis, immunoperoxidase staining was localized within the Sertoli cells only at stages VI-VIII of the spermatogenic cycle, which is just prior to spermiation. Intense staining was also evident throughout the interstitial tissue, including Leydig cells. The entire epithelium of the efferent ducts, including ciliated and nonciliated cells, was immunoreactive. A distinct pattern of immunostaining for lipocalin-type prostaglandin D synthase was observed in different regions of epididymis, suggesting a possible role in sperm maturation. Staining for lipocalin-type prostaglandin D synthase was strikingly absent in the initial segment. In caput epididymidis, staining was evident throughout the cell cytoplasm of principal cells with some cells more intensely stained than adjacent ones. In the corpus region, overall staining intensity decreased and appeared to be concentrated in the apical region of principal cells, but some cells were completely unreactive. Reaction product in the cauda region was heavily concentrated on microvilli and within the epididymal lumen. In all epididymal regions, expression of lipocalin-type prostaglandin D synthase was specific to epithelial principal cells; no immunoreactivity was apparent in other cell types. The specific localization of lipocalin-type prostaglandin D synthase within the testicular interstitial tissue, Sertoli cells, and principal cells of caput epididymidis strongly suggests that this protein plays an integral role in both the development and maturation of sperm.

Studies on Egg Zona Pellucida-Binding Molecule (Ligand) of Mouse Sperm. I. Sperm Maturation and Zona-Binding Ability.

The epididymis has three major regions; the caput, corpus and cauda. Sperm were obtained from each region, and their binding ability to egg zona pellucida was assayed. In the case of intact sperm: cauda sperm bound in high number, corpus sperm bound at an intermediate level (an average of 30% of cauda sperm binding level), and caput sperm bound rarely (1% of cauda sperm binding level). In the case of sperm immobilized by pretreatment with LaCl3, when eggs and sperm were shaken in order to allow them to come into collision with each other, the caput and corpus sperm were able to bind to zona pellucida as well as the caudal sperm could. These results suggest that the difference in binding efficiency of the native caput and corpus sperm to bind to the zona pellucida was not due to a defect in a ligand molecule on the plasma membrane but rather to their lack of motility. When a sperm-egg binding assay was done in the presence of a binding inhibitor of caudal sperm, the binding of caudal sperm was significantly inhibited by fetuin or N-acetylgalactosamine, but the binding of caput and corpus sperm was only slightly inhibited by them. We prepared a plasma membrane fraction from each epididymal sperm, and solubilized it with sodium dodecyl sulfate (SDS). Each SDS-solubilizable fraction inhibited the binding of corresponding epididymal sperm to egg zona pellucida but didn't inhibit the binding of sperm from different regions of epididymis. These results suggested that a ligand molecule of caudal sperm was different from that of caput and corpus sperm.

Cytochemical analysis of the anionic sites on the membrane of the stallion spermatozoa during the epididymal transit.

The structure, relative density, and distribution of anionic sites on the surface of epididymal and ejaculated spermatozoa were studied using polycationic ferritin (CF), colloidal iron hydroxide (CIH), various enzymatic treatments, methylation, and de-acetylation. Macro-molecules containing sugar residues, probably sialic acid, are part of the sperm membrane and show a characteristic distribution and density that is dependent of the sperm region and of its origin. Unlike the spermatozoa of other eutheria examined, the exposure of the stallion spermatozoa to neuraminidase treatment did not produce significant changes in the density of the negative charge of the sperm surface. The ability of purified neuraminidase to act only after saponification suggests that sialic acid may be present in the acetylated form. When CIH was used it is seen that the density of the negative charge is rather uniform within a particular segment of the spermatozoa and abruptly changes at the junction of morphologically distinct segments (Between the acrosomal and post acrosomal region of the sperm head and between the post acrosomal region and middle piece of the flagellum). The acrosome presented more negative groups dissociated at pH 1.8 than the postacrosomal region. A greater concentration of anionic sites over the flagellum was also observed when CIH and CF were used. This asymmetry probably represents different domains that may be related to specific functions. The cytochemical observations and the cellular electrophoretic mobility measurements did not show striking differences on the negative charge of sperm obtained from different regions of epididymis and ejaculates in contrast to previous results in other species. The spermatozoa collected from caput epididymidis bind CIH but not all population present equal response. In corpus and cauda region of epididymis the population displaying the capacity to bind CIH or CF significantly over the head and tail surface was the majority. This study corroborates that the distribution and density of terminal oligosaccharide residues on the sperm plasma membrane has species specific characteristics. The surface charge of the spermatozoa obtained either during the breeding or nonbreeding season, determined by measurements of cellular electrophoretic mobility and by the binding pattern of CIH and CF, does not show significant differences.

Identification of androgen-dependent proteins synthesized in vitro by the ram epididymis.

Protein synthesis has been investigated in different regions of the epididymis from normal rams, castrate rams, and castrate testosterone supplemented rams. Results show that there are few differences in the pattern of [35S]methionine-labelled proteins synthesized in different regions of the normal epididymis despite the variation in the morphology of the epithelial cells lining the duct. Three androgen-dependent proteins of molecular weights 24000, 64000 and approximately 200 000 were identified. Testosterone did not stimulate protein synthesis in the proximal caput epididymidis (region 1-3), suggesting that testicular fluid is important in maintaining the activity of epididymal cells in this area.

Characterization and androgen-dependence of proteins associated with luminal fluid and spermatozoa in the rat epididymis.

The proteins of epididymal luminal fluid and of spermatozoa recovered from different regions of the rat epididymis were examined by polyacrylamide gel electrophoresis under non-denaturing and denaturing conditions. Albumin (A) and four major pre-albumin bands (B-E) were observed in epididymal fluid from the cauda on non-denaturing gels. By comparing the migration of these bands with that of standard globular proteins on denaturing gels, the molecular weight of Bands B and C was estimated to be 16 000, Band D was 30 000 and Band E was 32 000. Bands D and E were apparently glycoproteins since they stained with periodic acid-Schiff's reagent and were bound by an affinity column of Concanavalin A. The pre-albumin proteins (B-E) were of epididymal origin since they (a) were not detected in blood serum, (b) were not detected in testicular extracts and (c) were still found after ligation of the efferent ducts. From the incorporation of radioactive methionine, Bands B and C were shown to be synthesized in the initial segment and caput. The regional distribution of luminal proteins indicated that protein D was added in the caput and cauda and protein E in the cauda. This regional origin of luminal proteins was confirmed by the altered protein profiles consequent upon the reduced fluid flow through the epididymis brought about by ligation of the efferent ducts. The androgen-dependence of epididymal protein synthesis was also investigated using radioactive methionine. Castration had little effect on total protein synthesis but resulted in the specific reduction of the synthesis of proteins B and C. Several changes were observed in the relative amounts of specific proteins extracted from spermatozoa from different regions of the epididymis and several of these proteins had molecular weights identical with those in luminal fluid. However, there was no evidence for any substantial binding to spermatozoa of the pre-albumin proteins (B-E) of luminal fluid.

Morphological changes in the boar spermatozoa at different regions of epididymis.

In order to obtain the information on the morphological changes occuring in sperm at various regions along the epididymis, forty one boars of Randrace breed were used for the examination of the morphology of sperm in epididymal content from four regions of epididymis. Samples were collected post mortem from the proxi-mal and distal parts of caput and cauda epididymides, respectively.The results obtained are as follows:There was a highly significant decrease in the incidence of abnormal sperm heads (pear-shaped, narrow at the base and narrow) during the passage from the proximal to the distal region of caput epididymidis. The decrease in the incidence of abnormal head with these types may be due to selective resorption or dissolution of sperm in the epithelium of caput epididymidis. Migration of cytoplasmic droplet from the prox-imal to distal position of middle-piece increased progressively during the passage of sperm through the epididymis, and largest migration took place from the proximal to distal region of caput epididymidis. While the incidence of bent tail sperm increased during the passage along the epididymis, it reached maximum in the proximal region of cauda epididymidis. These finding suggest that ability of selective sperm resorption in epididymal epithelium of caput is very active, and it contribute to the improvement semen picture after ejaculation. Studies on morphological characteristics of ejaculated sperm would be important for evaluation of the function at different regions of epididymis.