SOME EFFECTS OF UNILATERAL CRYPTORCHISM AND VASECTOMY ON SEXUAL DEVELOPMENT OF THE PUBESCENT RAM AND BULL

Abstract

SUMMARY The effects of cryptorchism were studied in pubescent lambs and calves by rendering the animals unilaterally cryptorchid soon after birth. The testis, epididymis, vas deferens and ampulla were smaller on the cryptorchid side but there was no difference as regards the seminal vesicles or bulbourethral glands. The histological appearance of the cryptorchid testis resembled that of the prepuberal normal testis; gonocytes survived in the cryptorchid testis for 16 weeks, but the supporting cells did not differentiate into Sertoli cells. When cryptorchid testes were returned to the scrotum after 8 weeks, some recovery of spermatogenesis was evident 8 weeks later, and testicular androgen concentration appeared to be normal again. In the cryptorchid testis there was a decrease in Δ5-3β-hydroxysteroid dehydrogenase activity and lipid content in the interstitial cells. In lambs, the absolute content of testicular androgen but not the concentration was reduced about ten times; the lower content could therefore be accounted for by the reduced size of the gonad. In the calf androstenedione remained the predominant androgen in cryptorchid testes up to 16 weeks of age but not in a testis cryptorchid for 16 weeks, from 32–48 weeks of age. The ampulla on the cryptorchid side was not only smaller, but contained also less fructose and citric acid; a similar effect could be produced by vasectomy. Presumably some testosterone must normally pass along the vas deferens into the testicular fluid and influence in this way the development of the ampulla.