Functional and morphological effects of hypophysectomy and androgen replacement in the rabbit epididymis

Summary The fertilizing ability of spermatozoa from the distal corpus epididymidis of 55 male rabbits of proven fertility has been determined after artificial insemination 1, 2, 3, 5, 7, and 11 days after hypophysectomy. A significant decrease in fertility was noted 3, 5, and 7 days after hypophysectomy. Testosterone propionate (2 mg/kg/day) given for 7 days to hypophysectomized rabbits maintained the fertilizing ability of spermatozoa from the corpus epididymidis when injections were started from the day of hypophysectomy or delayed by a week. The effect of hypophysectomy on the histological features of the epididymal epithelium were studied with light and electron microscopy. Regressive changes were observed: reduction in size of the stereocilia border and the endoplasmic reticulum 3 days after hypophysectomy followed by a decrease in tubular diameter and cell height, a reduction in size of the Golgi apparatus and an increase in number of lysosome-like figures and a vacuolization of the epithelium.These results are discussed in relation to the physiological requirements for sperm maturation.