Corpus Epididymidis Research Articles

Regulation of the gap junction interplay during postnatal development in the rat epididymis.

During postnatal development of the rat epididymis, a change in the expression of gap junction proteins, or connexins (Cxs), occurs, in which Gjb2 (Cx26) and Gja1 (Cx43) levels in the proximal epididymis are decreased, while Gjb1 (Cx32), Gjb4 (Cx30.3) and Gjb5 (Cx31.1) levels increase. The mechanism(s) responsible for the switch in Cx expression is unknown. The aim of this study is to identify the mechanisms responsible for the decrease in GJB2 protein levels and the increase in other Cxs during postnatal development. Results indicate that decreased Gjb2 expression for 48h does not alter the expression of other Cxs in RCE-1 principal cells, suggesting a lack of compensatory expression. Sequence analysis of both Gjb2 and Gjb1 promoters identified common multiple response elements to steroid hormones. Using RCE-1 cells, we observed that dexamethasone increased Gjb2 mRNA levels by twofold after 48h, while estradiol had no effect. Orchidectomy in rats resulted in a significant increase in GJB2 and decreased GJB1 in the caput and corpus epididymidis. Changes in Cxs protein levels were prevented by testosterone in orchidectomized rats. Similar results were observed in the prostate, another androgen-receptive organ. LNCaP cells, which are androgen-responsive, showed that exogenous dihydrotestosterone (DHT) decreased Gjb2 mRNA levels by approximately 50% concomitant with a 1.5-fold increase in Gjb1 levels. Using a GJB1 promoter construct we showed that DHT could induce transactivation of the luciferase transgene, while transactivation of two GJB2 promoters were unaltered. Results indicate that androgens and glucocorticoids regulate the expression of epididymal Cxs.

Investigation of male genital system anatomy in the New Zealand rabbit (Oryctolagus cuniculus L.).

Rabbits are frequently used in research because of their human-like biological structure. In the present study, 10 male rabbits were preferred. Arterial vascularization of the genital system organs were dissected. Morphometric and macroanatomical results of these organs were taken, and some organs were examined by magnetic resonance imaging (MRI). In this study, right testis length was measured at 67.24 ± 5.36 mm and left testis length was 62.25 ± 6.55 mm in New Zealand rabbits. Testicular weight was 10.21 ± 1.17 g on the right and 9.90 ± 1.15 g on the left. Right caput epididymidis 0.68 ± 0.08 g, left caput epididymidis 0.80 ± 0.13 g; right corpus epididymidis 0.14 ± 0.03 left corpus epididymidis 0.15 ± 0.03 g; right cauda epididymidis 1.87 ± 0.26 g left cauda epididymidis 1.90 ± 0.31 g. In the present study, right ductus deferens weight was 0.30 ± 0.29 g, and left ductus deferens weight was 0.25 ± 0.03 g; the ampulla ductus deferentis weight was 0.35 ± 0.16 g on the right side and 0.37 ± 0.16 g on the left side. The length of the vesicular gland glandula vesicularis was calculated as 18.54 ± 0.35 mm on the right and 17.55 ± 0.59 mm on the left. The width of the vesicular gland was measured as 16.54 ± 0.28 mm on the right and 16.70 ± 0.45 mm on the left. Vesicular gland weight was 0.91 ± 0.07 g on the right side and 0.96 ± 0.09 g on the left side. The prostate length was recorded as 11.68 ± 2.01 mm and width as 13.02 ± 1.38 mm. The length of the bulbourethral gland was 13.36 ± 2.00 mm on the right side and 12.39 ± 1.21 mm on the left. Its width was recorded as 6.73 ± 0.98 mm on the right and 5.80 ± 0.90 mm on the left. Respectively, it weighed 0.40 ± 0.20 g on the right and 0.44 ± 0.24 g on the left. The prostate consisted of three parts in rabbits: the proprostate, the corpus prostate and the paraprostate. The bulbourethral gland was a green lentil-sized gland found in pairs. It is thought that the obtained results will contribute to the scientific researches on male genital system in laboratory animals and other animal species, artificial insemination studies, reproductive system diseases and operations in rabbits.

Epididymal epithelial degeneration and lipid metabolism impairment account for male infertility in occludin knockout mice.

Occludin (OCLN) is a tight junction protein and Ocln deletion mutation causes male infertility in mice. However, the role of OCLN in male reproductive system remains unknown. In this study, we used an interdisciplinary approach to elucidate the underlying mechanism of male infertility in related to OCLN function, including Ocln knockout mice as well as a combined omics analysis and immunofluorescent labelling. Our results showed that the epididymis of Ocln-null mice displayed a phenomenon resembling epididymal sperm granuloma, which occurred especially in the junctional region between caput and corpus epididymidis. Sperm motility and fertilisation capacity were also impaired in these Ocln-null mice, accompanied by enlarged tubules in the proximal regions and degeneration in the distal regions of epididymis. Cellular localization analysis showed that OCLN immunofluorescence was enriched only in the apical junction of epithelial principal cells in the proximal regions of epididymis. Integrative omics analysis revealed the downregulation of gene clusters enriched in acid secretion and fatty acid metabolism in the Ocln-null epididymis, especially the enzymes related to the unsaturated arachidonic acid pathway. The number of proton-pump V-ATPase-expression clear cells, a key player of luminal acidification in the epididymis, declined drastically from prepubertal age before sperm arrival but not in the early postnatal age. This was accompanied by programmed cell death of clear cells and increased pH in the epididymal fluid of OCLN-deficient mice. The lipidomics results showed significantly increased levels of specific DAGs conjugated to unsaturated fatty acids in the Ocln-mutant. Immunofluorescent labelling showed that the arachidonic acid converting enzyme PTGDS and phospholipase PLA2g12a were prominently altered in the principal cells and luminal contents of the Ocln-mutant epididymis. Whereas the carboxylate ester lipase CES1, originally enriched in the WT basal cells, was found upregulated in the Ocln-mutant principal cells. Overall, this study demonstrates that OCLN is essential for maintaining caput-to-corpus epithelial integrity, survival of acid-secreting clear cells, and unsaturated fatty acid catabolism in the mouse epididymis, thereby ensuring sperm maturation and male fertility.

Anatomical Transcriptome Atlas of the Male Mouse Reproductive System During Aging.

The elderly males undergo degenerative fertility and testicular endocrine function that jeopardize the reproductive health and well-being. However, the mechanisms underlying reproductive aging are unclear. Here, we tried to address this by investigating the phenotypes and transcriptomes of seven regions of the male mouse reproductive tract: the testis, efferent ductules, initial segment, caput, corpus and cauda epididymidis, and vas deferens, in adult (3 months) and aged (21 months) mice. Quantitative PCR, immunohistochemistry, immunofluorescent staining, and enzyme-linked immunosorbent assay were performed for the analysis of gene expression in mice, human tissues, and semen samples. Aged male mice showed both systematic and reproductive changes, and remarkable histological changes were detected in the testis and proximal epididymis. Transcriptomes of the male reproductive tract were mapped, and a series of region-specific genes were identified and validated in mouse and/or human tissues, including Protamine 1 (Prm2), ADAM metallopeptidase domain 28 (Adam28), Ribonuclease A family member 13 (Rnase13), WAP four-disulfide core domain 13 (Wfdc13), and Wfdc9. Meanwhile, age-related transcriptome changes of different regions of the male reproductive tract were characterized. Notably, increased immune response was functionally related to the male reproductive aging, especially the T cell activation. An immune response-associated factor, phospholipase A2 group IID (Pla2g2d), was identified as a potential biomarker for reproductive aging in mice. And the PLA2G2D level in human seminal plasma surged at approximately 35 years of age. Furthermore, we highlighted Protein tyrosine phosphatase receptor type C (Ptprc), Lymphocyte protein tyrosine kinase (Lck), Microtubule associated protein tau (Mapt), and Interferon induced protein with tetratricopeptide repeats 3 (Ifit3) as critical molecules in the aging of initial segment, caput, caput, and cauda epididymidis, respectively. This study provides an RNA-seq resource for the male reproductive system during aging in mice, and is expected to improve our understanding of male reproductive aging and infertility.

GONADAL AND EXTRA-GONADAL SPERM RESERVES OF KANO BROWN BUCKS AS INFLUENCED BY SEASON AND FEEDING REGIME IN SEMI-ARID ZONE OF NIGERIA

The study was conducted to evaluate the effect of season and feeding regime on reproductive parameters of Kano Brown bucks. A total of fourty eight (48) bucks were used for this study which comprised sixteen (16) bucks per season. At the end of this study twelve (12) bucks, three from each treatment were orchidectomised. Twenty-four right and left testes were harvested, testicular weight (g) and length (cm) were measured. Epididymis was carefully separated from the testes using scapel blade and then separated into three parts (carput, corpus and cauda epididymides) weight (g) and length (cm) were also measured. Testes and epididymis were used to determine gonadal and extra gonadal (x 106)/g/testis which was done in the laboratory. Data collected were subjected to analysis of variance using Completely Randomized Design. The results of gonadal sperm reserves (x 106)/g/testis differed significantly among the seasons, dry season recorded the highest mean value (2896.83 x106)/g/testis whereas rainy season had the lowest mean value (2350.15 x106)/g/testis. Similarly, for extra gonadal sperm reserves, dry season also recorded the highest values (1736.00 x 106) followed by harmattan season (1037.50 x 106). Based on the results of this study, it could be concluded that season and feeding regime had a significant effect on gonadal and extra gonadal sperm/spermatid reserves of Kano Brown bucks. Breeding bucks should be raised during rainy and harmattan seasons.

Interaction of Epididymal Epithelia and their Secretions with Spermatozoa Supports Functional and Morphological Changes During Long-Term Storage in the Chinese Soft-Shelled Turtle (Pelodiscus sinensis).

Post-testicular maturation of spermatozoa is crucial for attaining the morphological and functional capabilities needed for successful fertilization. Epididymal epithelia offer a favorable environment for spermatozoa that are stored long term in the turtle epididymis; however, sperm-epithelial interactions during storage, which are enormously important for sperm functional and morphological maturation, are still largely unknown in turtles. The present study examined the epididymis during the sperm-storage period (November-April) in the Chinese soft-shelled turtle (Pelodiscus sinensis). Light and transmission electron microscopy were used to determine the cellular features of each epididymal segment (caput, corpus, and cauda) and their epithelial interactions with the spermatozoa. Spermatozoa were mainly located in the lumena of caput, corpus, and cauda epididymides. Numerous spermatozoa were bound to apical surfaces of the epithelia, and several were even embedded in the epithelial cytoplasm of the caput and corpus epididymides. No embedded spermatozoa were found in the cauda epididymis. In all epididymal segments, principal and clear cells showed the synthetic activity, evidenced by a well-developed endoplasmic reticulum network and high and low electron-dense secretory materials, respectively. Principal and clear cells in the caput and corpus segments showed embedded spermatozoa in electron-dense secretions and in the lipid droplets within the cytoplasm. No lysosomes were observed around the embedded spermatozoa. The lumena of the caput and corpus segments showed few apocrine and low electron density secretions. In the lumen of the cauda epididymidis, different secretions, such as holocrine with low and high electron density and their fragmentation, apocrine, and dictyosome, were found and are summarized. Altogether, sperm physical interactions with secretions either in the cytoplasm of epithelium or in the lumen may support the viability, morphological maintenance, and transfer of various proteins involved in long-term sperm storage in the turtle. This interaction could help us to understand the mechanisms of long-term sperm storage and provide more insights into the reproductive strategies of turtle sperm preservation.

Immunohistochemical Studies of αSMA in the Epididymis of African Four-Toed Hedgehog (Atelerix albiventris)

Abstract The epididymis plays an important role in sperm maturation, storage, transport and in the secretion of enzymes and proteins into the tubular lumen. In this study, we examined the histology, microstereology and immunohistochemical localization of alpha smooth muscle (αSMA) in the three regions of the epididymis of the African four-toed hedgehog (Atelerix albiventris). Ten adult males were captured from the wild in Ibadan, Nigeria, between May and October, 2016. The animals were euthanized and the epididymis (caput, corpus and cauda regions) were retrieved and fixed in buffered neutral formalin ahead of the paraffin technique, following standard procedures. The duct of the epididymis was lined by pseudostratified columnar epithelium comprising basal, principal and apical cells as well as intraepithelial lymphocytes in proximity to basal cells. The principal cells, the major cells encountered within the epididymal epithelium of the animal, decreased in population from the caput to the cauda epididymidis while the apical cells were more abundant in the cauda epididymidis. Positive reactions to αSMA were observed in the peritubular muscular coat of the epididymal duct as well as blood vessels across the three regions of the epididymis with the caput and cauda epididymidis showing stronger positive reactions compared to the corpus epididymidis. This study demonstrated that the histology, microstereology as well as the cellular constituents of the epididymal duct of the Atelerix albiventris are similar to those of other mammals with a slight variation. It has also highlighted variation in the localization of αSMA across the regions of the epididymis of the animal.

Organization of planar rafts, caveolae and steroid receptors on spermatozoa during development

Sperm membranes undergo progressive structural and functional modifications during epididymal maturation, capacitation and acrosome reaction. Though sperm membranes have raft microdomains, our understanding on the reorganization of membrane rafts during these events is limited. Using caveolin1 (CAV1) and ganglioside GM-1 as markers of membrane rafts, we studied the organization of sperm membrane rafts during epididymal maturation, in vitro capacitation and progesterone-induced acrosome reaction. We also evaluated the effect of raft disruption by methyl beta cyclodextrin on sperm hyperactivation, progesterone induced acrosome reaction and sperm-zona pellucida binding in vitro. CAV1 and ganglioside GM-1 showed transient non-overlapping localization pattern on sperm head during the intermediate phase of epididymal maturation and ended with co-localization on the acrosomal region toward the advanced stages of epididymal maturation and subsequent capacitation. CAV1 was excluded from sperm membrane rafts during capacitation and acrosome reaction. Progesterone receptor (PR) was present in the caveolar rafts of spermatozoa from testis, caput epididymidis and corpus epididymidis, but was not detected in that from cauda epididymidis. Further, capacitation was associated with the appearance of PR in non-caveolar rafts. Estrogen receptors ERα and ERβ, which were located in the caveolar rafts of spermatozoa from testis and epididymides, appeared in the non-caveolar rafts during capacitation and acrosome reaction. It appears that PR, ERα and ERβ were sequestered in the caveolar rafts of spermatozoa during epididymal maturation, and the exit of CAV1 from the membrane rafts overlying the acrosome during capacitation might free them from the sequestration that might trigger PR into action.

Sleep restriction in Wistar rats impairs epididymal postnatal development and sperm motility in association with oxidative stress.

Good sleep quality has a direct effect on the activity of the neuroendocrine-reproductive control axis and oxidative stress. Thus, the aim of the present study was to evaluate whether sleep restriction (SR) during the peripubertal period impaired the postnatal development of the epididymis in Wistar rats. After 21 days SR (18h per day), epididymides were collected on Postnatal Day (PND) 62 for evaluation of oxidative stress markers, inflammatory profile, sperm count and histopathological and stereological analyses; in addition, the motility of spermatozoa from the vas deferens was examined. SR significantly increased lipid peroxidation and glutathione levels in the caput and cauda epididymidis, and increased levels of total radical-trapping antioxidant potential in the caput epididymidis only. Neutrophil migration to the caput or corpus epididymidis was decreased by SR, and the size of the luminal compartment in the 2A region and the epithelial compartment in the 5A/B region was also decreased. In these regions, there was an increase in the size of the interstitial compartment. The percentage of immotile spermatozoa was higher in the SR group. In conclusion, SR affects epididymal postnatal development, as well as sperm motility, in association with increased oxidative stress and a decrease in the size of the epithelial compartment in the cauda epididymidis.

The tolerance of feline corpus and cauda spermatozoa to cryostress

Epididymal sperm preservation can be used to avoid the total loss of genetic material in threatened species. Spermatozoa from the corpus, as from the cauda, are motile and can undergo capacitation. Thus, they can potentially be preserved for assisted reproductive technologies. However, cryopreservation of spermatozoa has a direct detrimental effect on sperm quality. The aim of this study was to compare the chromatin stability and the survival rate of spermatozoa from the corpus and cauda epididymis after cryopreservation. Epididymal spermatozoa were collected and cryopreserved from the corpus and cauda of 12 domestic cats. Sperm motility, progressive motility, membrane integrity, acrosome integrity, and DNA integrity were evaluated before and after freezing thawing. The average total number of spermatozoa collected from the corpus was lower (10.2 × 106 ± 7.4) than that from the cauda epididymis (24.9 × 106 ± 14.4; P = 0.005). The percentage of spermatozoa with intact DNA did not differ significantly whether it was collected from the corpus or cauda regions and did not decrease after freezing thawing in either region. However, motility of spermatozoa from both regions was affected by the freezing thawing process with a significant decline in motility after thaw compared with fresh spermatozoa. A significant difference in the percentage of motile sperm between the corpus and cauda was observed after the freezing thawing process (P < 0.001). Although sperm motility was lower in postthaw spermatozoa from the corpus epididymidis than from the cauda, the rate of the reduction did not differ between regions. This study indicates that the cryopreservation process does not have a negative effect on chromatin stability of feline epididymal spermatozoa. Spermatozoa from the corpus region have a similar freezability as spermatozoa from the cauda region. Therefore, preservation of spermatozoa from the corpus and the cauda epididymidis might be of value in preserving genetic material from endangered or valuable felids.

Steroid regulation of early postnatal development in the corpus epididymidis of pigs

Development of the epididymis including blood-epididymal barrier formation is not required until sperm reach the epididymis peripuberally. Regulation of this development in the early postnatal period is largely unknown. The current objectives were to evaluate potential roles of endogenous estrogen and androgen signaling during early development of the corpus epididymidis and to determine the timing of formation of the blood-epididymal barrier in the pig. Effects of endogenous steroids were evaluated using littermates treated with vehicle, an aromatase inhibitor (letrozole) to reduce endogenous estrogens, an estrogen receptor antagonist (fulvestrant) or an androgen receptor antagonist (flutamide). Phosphorylated histone 3 immunohistochemistry was used to identify proliferating epithelial cells. Lanthanum nitrate and electron microscopy were used to analyze formation of the blood barrier in the corpus epididymidis. Reducing endogenous estrogens increased the number of proliferating corpus epithelial cells at 6 and 6.5 weeks of age compared with vehicle-treated boars (P<0.01 and P<0.001 respectively). Blocking androgen receptors did not alter proliferation rate at 6.5 weeks of age. Although barrier formation was similar between 6 and 6.5 weeks of age in vehicle-treated animals, intercellular barriers increased in letrozole-treated littermates at 6.5 weeks of age. Fulvestrant treatment, which should mimic aromatase inhibition for regulation through ESR1 and ESR2 signaling but potentially stimulate endogenous estrogen signaling through the G protein-coupled estrogen receptor (GPER), had the opposite effect on aromatase inhibition. These responses in conjunction with the presence of GPER in the corpus epididymidis suggest early corpus epididymal development is regulated partially by GPER.

Assessment of Freezability and Functional Integrity of Dromedary Camel Spermatozoa Harvested from Caput, Corpus and Cauda Epididymides

Assessment of Freezability and Functional Integrity of Dromedary Camel Spermatozoa Harvested from Caput, Corpus and Cauda Epididymides

Histological and morphometric studies on the dromedary camel epididymis in relation to reproductive activity

The reproductive efficiency of male dromedary camels under natural conditions is regarded to be low due to a relatively short breeding season and a long prepubertal period. This study was carried out to investigate the histological and morphometric changes in the Sudanese dromedary camel epididymis in relation to the breeding (rutting) and non-breeding (non-rutting) seasons at monthly intervals up to one year. Specimens were collected from different regions of the epididymis of 48 mature and healthy Sudanese male camels slaughtered at Tambul slaughter house in central Sudan. Paraffin sections of the caput, corpus and cauda regions of the epididymis were stained conventionally for general histology and morphometry. The epididymal stereociliated epithelium showed five types of cells: principal, basal, apical, halo and dark cells and the epithelium was surrounded by a thin layer of lamina propria and a circumtubular smooth muscle coat. No significant seasonal histological or morphometric changes were observed in the caput and corpus epididymides. However, a remarkable decrease in epididymal epithelial thickness and length of stereocilia with consequent increase in luminal diameter was observed in the cauda epididymidis during the rutting season; there was also an increase in the smooth muscle coat thickness.Thus, the results suggest that the epididymis of Sudanese dromedary camel is active throughout the year, but the activity remains low during winter and increases to its maximum during summer, especially during the rainy months.

Influence of age and sexual maturation on the expression of LH and FSH receptors and aromatase P450 in equine male reproductive tissues

Testicular function and maturation in male domestic animals is regulated by a complex interplay of endocrine, paracrine and autocrine factors. The objective of the present study was to characterize gene expression of the receptors for LH (LHR) and FSH (FSHR) as well as aromatase in equine epididymal and testicular tissue with regard to sexual maturity of stallions. We hypothesized tissueand age-related differences in the expression and localization of these genes. Tissue from testis and epididymis (corpus and cauda) was collected at routine castration of 21 sexually healthy stallions. They belonged to 4 different age groups: prepubertal ( 9 years, n 1⁄4 4). Changes in mRNA expression and protein localisation of LHR, FSHR and aromatase were analysed using quantitative real-time PCR (qRT-PCR) with GAPDH as reference gene, immunohistochemistry (IHC), and multiple immunofluorescence labelling. Statistical analysis was performed with the SPSS/PC statistics package (version 17.0 for windows, SPSS Inc., Chicago, IL, USA) Comparisons between age groups were done by KruskalWallis test with a subsequent Wilcoxon test. In testicular and corpus and cauda epididymal tissue collected from older stallions, the relative gene expression of aromatase in testicular parenchyma was significantly higher (p<0.05) than in animals of all other age groups. No differences in LHR and FSHR mRNA expression in testes were seen with respect to age. However, quantitative total expression of FSHR-mRNA in corpus and cauda epididymidis was significantly elevated (p<0.05) in older horses compared

Loss of Vascular Endothelial Growth Factor A (VEGFA) Isoforms in the Testes of Male Mice Causes Subfertility, Reduces Sperm Numbers, and Alters Expression of Genes That Regulate Undifferentiated Spermatogonia

Vascular endothelial growth factor A (VEGFA) isoform treatment has been demonstrated to alter spermatogonial stem cell homeostasis. Therefore, we generated pDmrt1-Cre;Vegfa(-/-) (knockout, KO) mice by crossing pDmrt1-Cre mice to floxed Vegfa mice to test whether loss of all VEGFA isoforms in Sertoli and germ cells would impair spermatogenesis. When first mated, KO males took 14 days longer to get control females pregnant (P < .02) and tended to take longer for all subsequent parturition intervals (9 days; P < .07). Heterozygous males sired fewer pups per litter (P < .03) and after the first litter took 10 days longer (P < .05) to impregnate females, suggesting a more progressive loss of fertility. Reproductive organs were collected from 6-month-old male mice. There were fewer sperm per tubule in the corpus epididymides (P < .001) and fewer ZBTB16-stained undifferentiated spermatogonia (P < .003) in the testes of KO males. Testicular mRNA abundance for Bcl2 (P < .02), Bcl2:Bax (P < .02), Neurog3 (P < .007), and Ret was greater (P = .0005), tended to be greater for Sin3a and tended to be reduced for total Foxo1 (P < .07) in KO males. Immunofluorescence for CD31 and VE-Cadherin showed no differences in testis vasculature; however, CD31-positive staining was evident in undifferentiated spermatogonia only in KO testes. Therefore, loss of VEGFA isoforms in Sertoli and germ cells alters genes necessary for long-term maintenance of undifferentiated spermatogonia, ultimately reducing sperm numbers and resulting in subfertility.

Expression of the rhesus glycoproteins, ammonia transporter family members, RHCG and RHBG in male reproductive organs

The rhesus glycoproteins, Rh B glycoprotein (RHBG) and Rh C glycoprotein (RHCG), are recently identified ammonia transporters. Rhcg expression is necessary for normal male fertility, but its specific cellular expression is unknown, and Rhbg has not been reported to be expressed in the male reproductive tract. This study sought to determine the specific cellular expression of Rhcg, to determine whether Rhbg is expressed in the male reproductive tract, and, if so, to determine which cells express Rhbg using real-time RT-PCR, immunoblot analysis, and immunohistochemistry. Both Rhbg and Rhcg were expressed throughout the male reproductive tract. In the testis, high levels of Rhbg were expressed in Leydig cells, and Rhcg was expressed in spermatids during the later stages of their maturation (steps 13-16) in stages I-VIII of the seminiferous epithelium cycle. In the epididymis, basolateral Rhbg was present in narrow cells in the initial segment, in principal cells in the upper corpus, and in clear cells throughout the epididymis. Apical Rhcg immunolabel was present in principal cells in the caput and upper corpus epididymidis and in clear cells in the middle and lower corpus and cauda epididymidis. In the vas deferens, apical Rhcg immunolabel and basolateral Rhbg immunolabel were present in some principal cells and colocalized with H(+)-ATPase immunolabel. We conclude that both Rhbg and Rhcg are highly expressed in specific cells in the male reproductive tract where they can contribute to multiple components of male fertility.

Two periods of total testicular regression are peculiar events of the annual reproductive cycle of the black Myotis bat, Myotis nigricans (Chiroptera: Vespertilionidae)

Myotis nigricans presents few and controversial reproductive data, which indicate geographical variation in reproduction. Thus, this study aimed to evaluate the seasonal modifications in testicular and epididymal morphologies in a tropical environment, submitting these organs to morphometric and immunohistochemical analysis. The observations revealed that this species presents two peaks of spermatogenic activity followed by two periods of total testicular regression (a quiescent pre-pubertal-like morphology, where only Sertoli cells and spermatogonia could be observed), in the same annual reproductive cycle, which seem to be only indirectly influenced by abiotic factors. This testicular behaviour seems to be synchronised with the caput and corpus epididymidis, but not with the cauda epididymidis, which presents aspects of sperm storage in May-June. The control of this variation seems to be directly linked to the expression of the androgen receptor, since, throughout the year, it is high in periods of testicular recrudescence and low in periods of deactivation. It is not thought to be directly linked to apoptosis, which is more pronounced in periods of recrudescence than in periods of regression.

Expression of 11β‐Hydroxysteroid Dehydrogenase Type 1 and Glucocorticoid Receptors in Reproductive Tissue of Male Horses at Different Stages of Sexual Maturity

Glucocorticoids (GCs) as mediators of the stress response may affect Leydig cell function by inhibiting either luteinizing hormone receptor expression or testosterone biosynthesis. The isozymes 11β-hydroxysteroid dehydrogenase (11βHSD) 1 and 11βHSD2 control the intracellular cortisol levels. Little is known about the effects of stress on fertility in the equine. The objective of the present study was to determine the presence and cellular localization of glucocorticoid receptors (GCR) and glucocorticoid-metabolizing enzymes (11βHSD1 and 11βHSD2) in equine epididymal and testicular tissue with special regard to sexual maturation. Testicular and epididymal tissue was collected from 21 healthy stallions, and four age groups were designed: pre-pubertal, young, mature and older horses. Immunohistochemistry (IHC) analysis and quantitative real-time PCR (qRT-PCR) were used. Pre-pubertal horses showed higher testicular gene expression of 11βHSD1, 11βHSD2 and GCR than horses of all other groups (p < 0.05). A positive intranuclear immunoreaction for GCR was seen in epithelial cells of caput, corpus and cauda epididymidis and in Leydig cells. Significant differences (p < 0.05) between age groups occurred. The number of Leydig cells staining positive for GCR was highest in immature stallions (p < 0.05). The enzyme 11βHSD1 was localized in epithelial cells of the caput and corpus epididymidis and in Leydig cells. As determined by enzyme assay, nicotinamide adenine dinucleotide (NAD)-dependant dehydrogenase (oxidation) activity was not detected in testicular tissue from immature stallions but in all other age groups (n = 3 per group). Results of this study suggest a contribution of GCs to maturation of male reproductive tissue in horses. In mature stallions, expression of 11βHSD enzymes and the oxidative 11βHSD activity in Leydig cells and epididymal basal and principal cells suggest a protective role on these tissues contributing to physiological intracellular glucocorticoid concentrations.

Rhox5 Rules in an Evolving Saga of Reproductive Diversity

Rhox5 Rules in an Evolving Saga of Reproductive Diversity

The effects of prepubertal epididymal ligation upon androgen receptor distribution in the rat caput epididymis

The aim of the present study was to investigate the androgen receptor (AR) distribution in epididymal cells of developing rats and the effects of prepubertal epididymal obstruction upon AR distribution in the rat caput epididymis. At 15 days of age, the young rats were divided at random into groups for epididymal ligation or sham operation. In the ligation group the corpus epididymides were ligated bilaterally; in the sham group only laparatomy was performed. Both groups were sacrificed at 21, 56, 90, 120 days. The epididymes were removed, fixed in Bouin's fixative and embedded in paraffin wax. The tissues were sectioned at 5 &amp;mu;m and stained using the microwave stimulated antigen retrieval technique for immunohistochemistry. The features of the immunohistochemical staining of caput epididymal cells for the AR were similar across both groups. The operation did not affect AR distribution in caput epididymis. Positive immunohistochemical staining for the AR appeared in nuclei but not in the cytoplasm of caput epididymal cells at all ages beginning from 21 to 120 days old. The staining intensity of AR-positive cells did not change depending on age. In the caput epididymis, immunostainable AR were found in tubular epithelial cells (principal cells, basal cells and apical cells) and interstitial stromal cells (peritubular smooth muscle cells). There were no significant histological alterations in epididymal epithelium.