Vasectomy in rhesus monkeys. IV. Electron microscopic studies of the seminiferous epithelium.

Abstract

AbstractStudies were undertaken to assess the fine structural effects of vasectomy upon the rhesus monkey testis, using 27 monkeys subjected to one of three surgical techniques: control sham operation (COS), unilateral silk vasoligation (USV), or unilateral clasp vaso‐occlusion (UCV). The monkeys were sacrificed from 1 to 66 weeks after surgery; tissues were fixed in glutaral‐dehyde in collidine buffer and processed for electron microscopy (EM) using routine techniques. No alterations were noted in the seminiferous epithelium of any COS animal; only focal lesions were found in vasectomized animals. These changes correlated with length of time post‐vasectomy, a finding consistent with earlier light microscopic studies (Heidger et al., '78). Even at the longest post‐operative periods studied, spermatogenesis appeared in most animals to be normal. One animal exhibited areas in which the seminiferous epithelium consisted of Sertoli cells and spermatogonia, only. The seminiferous epithelium of approximately one‐third of other animals, both on the vasectomized and contra‐lateral sides, exhibited such alterations as development of extensive infoldings and duplication within the basal lamina, and presence within the basal Sertoli cell cytoplasm of late spermatids and sperm tails. These alterations were observed in both UCV and USV animals. The presence of such late germ cells in the basal Sertoli cell cytoplasm was noted by light microscopy; however, lu‐minal spermiophages encountered in one animal at the light microscopic level were not detected in our EM study, which underscores the limitations of EM as a survey technique. All UCV animals developed spermatic granulomas of the vas, whereas only 3 of 13 USV animals developed such granulomas. It does not appear that the alterations exhibited by the animals in this study would necessarily dispose toward impaired spermatogenesis following vasovasostomy.