Fate of Spermatozoa in the Male: 1. Quantitation of Sperm Accumulation after Vasectomy in the Rabbit

Whether or not a significant number of spermatozoa sequestered in the male tract may dissolve there or be phagocytized by epithelial cells of the epididymis and vas deferens is a matter of basic interest and is central to understanding of the immediate sequelae of vasectomy. To investigate this, groups of rabbits were vasectomized bilaterally and left for 1, 2, 4 and 6 months. The numbers of spermatozoa found in the epididymis and vas deferens after each time interval were equivalent to the numbers estimated to be produced over the same period by the testis. Moreover, testicular sperm production did not change while the ducts remained intact after vasectomy. By contrast, two exceptions in which lesions developed in the corpus epididymidis showed degenerative changes in the germinal epithelium. These results demonstrate that while the epithelium of the duct remains intact, there is no significant resorption or dissolution of spermatozoa in the vas deferens and epididymis of the rabbit.