| Abstract: | The capacity of various androgens to virilize the differentiating mammary gland in the female rat fetus has been determined. Testosterone, 5alpha-androstane-3alpha, 17beta-diol (3alpha-diol), and dihydrotestosterone (DHT) virilize the anlagen of the mammary gland by suppressing nipple formation but 5alpha-androstane-3beta, 17beta-diol, androsterone, and dehydroepiandrosterone sulfate do not affect female mammary differentiation. However, unlike the genitalia and wolffian ducts of the female rat fetus in which the masculinizing potency of DHT and 3alpha-diol is greater than that of testosterone, testosterone is more potent than its metabolites DHT and 3alpha-diol, in virilizing the mammary gland. The results suggest that testosterone is the fetal androgen mediating masculine development of the mammary gland. |
