Postvasectomy Alterations in Protein Synthesis and Secretion in the Rat Caput Epididymidis Are Not Repaired After Vasovasostomy

Despite more than 30 million vasectomies, the ultrastructural features of the epithelium of the vas deferens (VD) of healthy fertile men, as well as the effects of vasectomy at both proximal (testicular) and distal (abdominal) regions of the VD relative to the initial site of incision, have yet to be fully elucidated. In the present study, the VD from 22 fertile men undergoing vasectomy and 7 vasectomized men undergoing vasectomy reversal were examined by light and transmission electron microscopy. In fertile men, aside from cellular organelles involved in endocytosis and merocrine secretion, the epithelial principal cells showed protrusions of their apical cytoplasm between adjacent microvilli, referred to as “apical blebs.” The latter contained solely numerous ribosomes/polysomes and few endoplasmic reticulum (ER) cisternae, unlike the presence of lysosomes, lipofuscin granules, mitochondria, and the Golgi apparatus in the apical principal cell cytoplasm, suggesting the segregation of organelles within blebs. Many apical blebs presented a bulbous extremity with a thin stalklike attachment connecting them to the apical principal cell surface, while others appeared to be isolated and well removed from it, suggesting that blebs are capable of detaching and being liberated into the lumen. We hypothesize that apical blebs represent a type of secretion, referred to as “apocrine secretion.” In men undergoing vasectomy reversal, the VD proximal (testicular) to the vasectomy site showed a reduction in the size of principal cells and their microvilli and in the number of apical blebs. In contrast, the lumen of the VD distal (abdominal) to the vasectomy site was virtually abolished, with the epithelium reduced to a flattened layer of cells showing a paucity of organelles and no apical blebs, suggesting that these cells become undifferentiated in the absence of seminal fluids. Taken together, these data may explain, in part, the decreased pregnancy rate noted after vasectomy reversal despite a patent anastomosis.

Ultrastructural Features of the Vas Deferens From Patients Undergoing Vasectomy and Vasectomy Reversal

ANDONIAN,

JARVI,

ZINI

et al. 2002

Postweaning Exposure to Gossypol Results in Epididymis‐Specific Effects Throughout Puberty and Adulthood in Rats

ROMUALDO,

KLINEFELTER,

KEMPINAS

2002

Gossypol, a yellow pigment found in cottonseeds, well known for its antifertility properties in animals, has been used as a contraceptive by men. The aims of this work were to evaluate the effects of gossypol throughout sexual development of male rats and to provide additional data to clarify the target site or sites of this compound in the male reproductive system. Gossypol (15 mg/kg per day) was given to animals from weaning through prepuberty (41 days), early puberty (51 days), puberty (61 days), and sexual maturity (91 days). Ventral prostate weight and fructose levels were similar in control and treated rats, suggesting that androgen levels were normal. No histological effects on the testis were detected, but there was a significant decrease in the sperm concentration in the cauda epididymidis of gossypol‐treated animals killed at 61 and 91 days, as well as a significant increase in abnormal sperm in the vas deferens of treated animals. Moreover, the histology of the cauda epididymidis of the rats treated throughout puberty (ie, until days 51 and 61) showed a great number of round bodies in the lumen of the epididymis. These structures stained for the epididymis‐specific protein E. Collectively, the data demonstrate that the epididymis is a target of gossypol when postweaning exposure extends throughout pubertal development, and that whereas more subtle histological effects commence around puberty, indicators reproductive competence are compromised in adulthood.

Monoclonal Antibodies to Epididymis‐specific Proteins Using Mice Rendered Immune Tolerant to Testicular Proteins

Joshi

Ranpura

Khan

et al. 2003

Monoclonal antibodies (mabs) have been used as a powerful tool for identification of newer sperm proteins. However, conventional hybridoma technology rarely provides chance to obtain mabs to epididymal proteins. To increase this chance, we have used an alternate method of neonatal tolerization. In this protocol, animals were tolerized at birth using testicular proteins followed by immunization with cauda epididymal sperm protein (which is a cocktail of proteins both from testicular and epididymal origin). This protocol induced a specific immune response to epididymal sperm proteins. Spleen from one of these animals was then used for preparation of mabs. This fusion resulted in a number of mabs reacting specifically to epididymal proteins. Although mabs identified a protein of approximately similar molecular weight on 1-dimensional Western blot analysis, there were differences in regional localization on rat sperm as seen by indirect immunofluorescence. Immunohistochemical localization of these proteins in rat epididymis showed region specific synthesis. The synthesis of proteins was seen in the distal caput epididymis, and maximum expression was seen in supranuclear region of corpus epithelium. The proteins were localized on sperm from corpus and cauda region. Epididymis specific synthesis of the proteins and agglutinating nature of the mabs to these underlines the functional importance of these proteins in sperm maturation in epididymis. These antibodies could therefore, be used as tools for understanding the physiology of maturation of sperm in epididymis and role of the epididymal protein in fertilization.