Ultrastructure of the testis epididymis and vas deferens of the rabbit after vasectomy.

The reproductive tract of adult male rabbits was studied with the light and electron microscopes at intervals of up to 9 months after bilateral vasectomy or a sham operation. The epididymis and proximal part of the vas deferens of vasectomized rabbits became greatly distended with sperm. In 3 of 5 animals killed 6-9 months after vasectomy however the epididymis and vas deferens were less distended than in other vasectomized rabbits and there was evidence that sperm escaped the duct system and underwent phagocytosis by macrophages in a spermatic granuloma. In spite of the distention the epithelium of the epididymis and vas deferens of vasectomized rabbits was not flattened but retained a normal height and was funtionally active as indicated by the persistence of normal cell organelles including vesicles vacuoles and lysosomes involved in absorption and smooth endoplasmic reticulum that may have a role in secretion. Testes remained normal up to 6 months after vasectomy. However in 1 rabbit that was killed 6 months after vasectomy and had a spermatic granuloma spermatogeneis was depressed. Multinucleate spermatids were present in unusually high numbers in all 3 rabbits killed 9 months after vasectomy and they were most abundant in the animal in which the epididymis and vas deferens were the most greatly distended.(FULL TEXT)