Alpha-glucosidase activity and sperm motility

We correlated the activity of alpha-glucosidase in seminal plasma with the motility and differential motility of sperm. Significant positive correlations were found between the alpha-glucosidase activity and both motility and the percentage sperm with good forward progression. This supports the use of alpha-glucosidase in semen as a marker of epididymal function and specifically of the development of motility.     

Mouse Sperm Rosette: Assembling During Epididymal Transit,in vitro Disassemble,and Oligosaccharide Participation in the Linkage Material

In many mammals, sperm associations had been observed, but not in the mouse. In this work, mouse sperm rosettes are morphologically described inside the epididymis and during its dissolution in a culture medium. Also characterized are the saccharides present in the linking material. Sperm association and other epididymal actions are supported by sperm during epididymal transit and are verified at the caudal region, suggesting a relation between epididymal transit and sperm maturation. In drops of epididymal content obtained from distal (cauda), but not from proximal (caput and corpus) regions; dissolved in culture medium, rosettes appear to be 10 to 15 motile sperm joined by their heads. After 3 min, sperm progressively detach, disassembling the rosette. These structures are studied by several techniques, including optic, electronic (scanning electron microscopy and transmission electron microscopy), and video microscopy. At the ultrastructural level, a dense network of electron‐dense material was observed between sperm heads, joining them. Based on previous works in rat, several lectins were used to characterize the type of saccharides present in this linking material. To avoid the contact between sperm and epididymal fluid from distal region—that probably exerts an influence on sperm association—a ligature was placed between caput and corpus. This epididymal content isolated from caput did not display any rosettes after 28 days. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.     

Somatic von hippel-lindau mutation in clear cell papillary cystadenoma of the epididymis

Papillary cystadenoma of the epididymis is an uncommon benign lesion that may occur sporadically or as a manifestation of von Hippel—Lindau (VHL) disease. Neither immunohistochemical studies nor molecular genetic analyses of the VHL gene have been reported previously for this lesion. The authors describe two cases of clear cell papillary cystadenoma of the epididymis, both of which were initially confused with metastatic renal cell carcinoma. Both lesions showed positive immunohistochemical staining for low and intermediate molecular weight keratins (Cam 5.2 and AE1/AE3), EMA, vimentin, α₁-antitrypsin, and α₁-antichymotrypsin. Each was negative for CEA. Because clear cell papillary cystadenoma is similar to renal cell carcinoma histologically, and because both occur as components of the von Hippel—Lindau disease complex, the authors analyzed both cases for the presence of mutations in the VHL gene. A somatic VHL gene mutation was detected in one of the two tumors by polymerase chain reaction followed by single-strand conformation polymorphism analysis. Direct sequencing revealed a cytosine to thymine transition at nucleotide 694, resulting in the replacement of an arginine with a stop codon after the sixth amino acid of exon 3. As the VHL gene is believed to function as a tumor suppressor gene, VHL gene mutations may play a role in the initiation of tumorigenesis in sporadic cystadenomas of the epididymis.     

Microvasculature of the buffalo epididymis

The microvasculature of the water buffalo (Bubalus bubalis) epididymis was investigated using light (LM), scanning electron (SEM), and transmission electron (TEM) microscopy techniques. SEM analysis of the buffalo epididymis showed fenestrations that occupied ovoid inside the endothelium of the postcapillary venules located in the caput, corpus, and cauda. They varied in shape and dimension, but more importantly, they connected the venules of the blood vascular system to the capillaries of the peripheral lymphatic vascular system. Morphofunctional analysis of these connections suggests that the microvasculature of the buffalo epididymis plays a role in facilitating the circulation of biologically active substances, and the absorption and secretion processes necessary for the survival and maturation of spermatozoa. The lymphatic capillaries at the connection points formed a network of variously sized polygonal links. These capillaries then converged to form the precollector lymphatic vessels, which in turn converged with the larger vessels originating from the testis. It was further noted that in the capillary endothelium there were no fenestrations, and in the large veins there were many diverticula. These diverticula appear to play a role in the regulation of the seasonal variations of the blood reflux. In general, the microvascular architecture of the buffalo epididymis, particularly its connection to the lymphatic vascular system, appears to play an important role in the absorption and secretion processes of the epididymal epithelium. Anat Rec 266:58–68, 2002. © 2002 Wiley‐Liss, Inc.     

Claudin‐7 Expressed on Lateral Membrane of Rat Epididymal Epithelium does not Form Aberrant Tight Junction Strands

Claudins are integral membrane proteins at tight junctions (TJs) and form TJ strands. In the present study, we found that claudin‐7 was localized along the entire lateral membranes of epididymal epithelium, including the apical junctional region throughout the epididymis, but claudin‐8 was restricted to the apical junctional region. This finding raises the possibility that aberrant TJ strands may be formed on lateral membranes. Thus, we focused on examining whether TJ strands exist on lateral membranes of epididymal epithelium. Freeze‐fracture electron microscopy showed that aberrant TJ strands were observed in only a few principal cells in all segments of the epididymis except for the initial segment, indicating that the occurrence of aberrant strands is very rare. Aberrant TJ strands were smooth and not subdivided into individual particles in the protoplasmic face, and complementary grooves in the extracellular face were almost free of particles. Aberrant TJ strands in the distal caput and corpus epididymis were accompanied by many vesicle‐like structures but those in the proximal caput and cauda epididymis were not. These results suggest that most of claudin‐7 in lateral membranes may exist in a nonpolymerized form and may play some different roles other than the formation of TJ strands, for example, in the formation of a pool of claudin proteins or in the reinforcement of cell adhesion. Anat Rec, 1431‐1438, 2007. © 2007 Wiley‐Liss, Inc.     

The current perspective on genetic and epigenetic factors in sperm maturation in the epididymis

Male infertility affects approximately 30% of infertile couples. As spermatozoa mature in the epididymal lumen, their potential for mobility increases, and their protein, lipid and small RNA (sRNA) content changes, whereas capacitation and fertilisation take place in the female reproductive tract. Both of the latter processes are affected by maturation, because impaired maturation causes premature capacitation and fertilization. The epididymis produces a suitable environment for sperm maturation via ion transport, vesicle secretion and protein matrix formation. The microenvironment for sperm maturation varies in three broad segments: the caput, the corpus and the cauda epididymis. Epididymosomes transfer proteins, lipids and sRNAs from the epididymal epithelium to spermatozoa and genetic alterations of epididymal genes can lead to decreased sperm motility, morphological abnormalities of spermatozoa and subfertility. Genetic factors are involved in all aetiological categories in male infertility. However, studies conducted on the genes involved in epididymal functions are limited. The sRNA content of spermatozoa changes during epididymal migration, and these sRNAs play a role in embryo development and epigenetic inheritance. This review aims to clarify the role of the epididymal epithelium in the maturation of spermatozoa in light of the current molecular genomic knowledge.     

Human Sperm Immotility Caused by Degeneration in the Epididymis

The maturation of human sperm normally takes place in the epididymis[1 ] .During epididymal maturation,sperm undergo physiological and biochemicalmodifications. One of the most prominent changes in sperm is the development ofsperm' s ability to move. Fully mature sperm demonstrate active,progressivemovement.However,some infertile patients presented very low sperm motility andeven totally immotile sperm in their ejaculates[2～ 4] .Unfortunately,in some suchcases,the mechanisms of sperm immotil…     

The fertilizing ability of human epididymal sperm

Purpose: Membrane cofactor protein (MCP), CD46, whose primary function is to protect host cells from homologous complement, has been presumed to serve as a sperm adhesion molecule for oocytes. The purpose of this study was to clarify the relationship between the properties of MCP expressed on epididymal sperm and their fertilizing ability in a recently developed strategy for assisted reproduction. Methods: We collected ejaculated sperm from normal subjects and epididymal sperm from vasectomized subjects and patients with congenital absence of the vas deferens. Western blotting and cofactor activity assay were performed to investigated the structural and functional properties of MCP. Results: Epididymal spermatozoa which showed a reduced fertilizing ability tended to react poorly with antibodies against MCP and also showed low cofactor activity, indicating weak complement regulatory activity compared to that of ejaculated spermatozoa. Conclusions: MCP is sufficiently expressed in ejaculated sperm in men with a normally developed epididymis but is diminished in epididymal sperm from men with congenital or acquired obstruction of the vas deferens.     

Glutamic acid concentration in human semen--its origin and significance

Glutamic acid content of semen was determined photometrically in over 400 semen specimens. Glutamatic acid content was found to increase proportionately to temperature in the first few hours post ejaculation. The glutamate estimation should therefore be performed on semen at 30 min. after ejaculation. The frequency distribution of glutamic acid concentration with 400 unselected specimens, 50 "normozoospermias" as well as 42 azoospermias is shown. The mean value of normozoospermias was 10.6 mg% (+/- 4.6 mg%) that of azoospermias 7.7 mg% (+/- 4.7 mg%). There was no correlation found between glutamic acid content and pH value. A correlation however, was demonstrated between glutamic acid and following: sperm count, citrate concentration, gamma-GT and carnitine. No correlation to fructose content was detectable. That suggests that glutamate gets to the ejaculate with the secretions from the prostate gland and epididymis whereas the seminal vesicles do not play a role in the level in the total semen.     

Altered gene expression during rat Wolffian duct development following di(n-butyl) phthalate exposure.

Di(n-butyl) phthalate (DBP) is a common plasticizer and solvent that disrupts androgen-dependent male reproductive development in rats. In utero exposure to 500 mg/kg/day DBP on gestation days (GD) 12 to 21 decreases androgen biosynthetic enzymes, resulting in decreased fetal testicular testosterone levels. One consequence of prenatal DBP exposure is malformed epididymides in adult rats. Reduced fetal testosterone levels may be responsible for the malformation, since testosterone is required for Wolffian duct stabilization and their development into epididymides. Currently, little is understood about the molecular mechanisms of Wolffian duct differentiation. The objective of this study was to identify changes in gene expression associated with altered morphology of the proximal Wolffian duct following in utero exposure to DBP. Pregnant Crl:CD(R) (SD) rats were gavaged with corn oil vehicle or 500 mg/kg/day DBP from GD 12 to GD 19 or 21. There were only small morphological differences between control and DBP-exposed Wolffian ducts on GD 19. On GD 21, 89% of male fetuses in the DBP dose group showed marked underdevelopment of Wolffian ducts, characterized by decreased coiling. RNA was isolated from Wolffian ducts on GD 19 and 21. Together with empirical information, cDNA microarrays were used to help identify candidate genes that could be associated with the morphological changes observed on GD 21. These candidate genes were analyzed by real-time RT-PCR. Changes in mRNA expression were observed in genes within the insulin-like growth factor (IGF) pathway, the matrix metalloproteinase (MMP) family, the extracellular matrix, and in other developmentally conserved signaling pathways. On GD 19, immunolocalization of IGF-1 receptor protein demonstrated an increase in cytoplasmic expression in the mesenchymal and epithelial cells. There was also a variable decrease in androgen receptor protein in ductal epithelial cells on GD 19. This study provides insight into the effects of antiandrogens on the molecular mechanisms involved in Wolffian duct development. The altered morphology and changes in gene expression following DBP exposure are suggestive of altered paracrine interactions between ductal epithelial cells and the surrounding mesenchyme during Wolffian duct differentiation due to lowered testosterone production.