Fine structure of the langur monkey vas deferens and possible role of changes following vasectomy in the success or failure of the vasovasostomy

Studies on the ultrastructure of the vas deferens have been carried out in control, vasectomized (6 and 24 months) and vasovasostomized (12 months) la ngur monkeys (Presbytis entellus entellus Dufresne). Vas deferens epitheliu m of the control animals depicted four types of cells, viz. the basal cells , principal cells, mitochondria-rich or apical cells and pencil or dark cel ls. The basal cells were short, cuboidal in nature with prominent nuclei, a nd contained sparse cytoplasmic organelles. The principal cells were charac terized by the presence of nuclei with irregular outline and intranuclear e lectron-dense granules, well-developed Golgi bodies with prominent secretor y vesicles, cisternae of rough endoplasmic reticulum, mitochondria, free ri bosome particles, lysosomes and stereocilia in the cytoplasm, suggesting an active secretory role, as well as the absorptive functions of the cells. T he mitochondria-rich cells consisted of numerous mitochondria, and other cy toplasmic organelles were sparse. The pencil cells were dark, slightly comp ressed and situated between the principal cells. Vasectomy resulted in redu ction of cytoplasmic volume and vacuolization of the cytoplasm, especially in the Golgi region of the principal cells. Rough endoplasmic reticulum and mitochondria were poorly defined. Vasovasostomy showed no appreciable impr ovement in the configuration of the cytoplasmic organelles. The results sug gest that a persistent reduced secretory activity of the cells following va sectomy and vasovasostomy might also be one of the factors responsible for unsuccessful vasovasostomy.