THE EFFECTS OF LIGATION OF THE VASA EFFERENTIA AND VASECTOMY ON TESTICULAR FUNCTION IN THE ADULT RAT

Abstract

SUMMARY The effects of ligation of the vasa efferentia and vasectomy were studied in adult rats, using the periodic acid-fuchsin sulphurous acid staining technique for the identification of stages of the 'seminiferous cycle'. The operations were performed unilaterally, the testis and the efferent ducts on the contralateral side serving as controls. The animals were killed at intervals ranging from 3 hr. to 28 days after ligation of the vasa efferentia, and 3 hr. and 90 days after vasectomy. Ligation of the vasa efferentia was followed by an increase in the diameter of the seminiferous tubules and in testicular weight which reached its peak at 36 hr. Thereafter both decreased progressively, the shrinkage being associated with degeneration of the seminiferous epithelium. Thus by 28 days after operation the weight of the treated testis was halved and the seminiferous epithelium was limited to a single row of cells. The pattern of degeneration of germ cells largely depended on their developmental stage: spermatocytes and spermatids showed signs of more severe damage than spermatogonia or mature spermatozoa. The changes among the spermatocytes and spermatids similarly varied according to their developmental stage. Vasectomy did not affect the process of spermatogenesis. The operation was followed by a temporary increase in the weight of the epididymis and by the formation of spermatoceles on the cut testicular end of the vas deferens.