Serum gonadotropins in the rat after prenatal damage to the testes by busulfan and their reaction to cryptorchidism, castration and administration of testosterone.

Adult male rats prenatally treated with 1,4-bis-(methanesulfonyloxy)-butane (busulfan), which damages the gonocytes, undergo cryptorchidization, castration or testosterone treatment and the FSH, LH and testosterone levels in serum are measured. Basal values of these hormones do not differ from those of controls. After cryptorchidization FSH levels rise but the LH levels do not. Following orchidectomy both hormone levels increase significantly. Application of testosterone in various doses increases FSH in normal animals but not in busulfan treated rats 24 h post infectionem. FSH and LH levels 7 days after administration do not differ from controls. According to the hypothesis that the FSH release depends on an inhibin from the testes, these experiments show evidence for inhibin being produced only in the Sertoli cells.