Effects of neonatally administered-testosterone propionate on the development of target organs of sex hormones and the induction of mammary carcinomas by 7, 8, 12-trimethylbenz (a)anthracene in female Sprague-Dawley rats.

Female Sprague-Dawley rats were given 1.25mg testosterone propionate subcutaneously within 24 hours after birth and 30mg 7, 8, 12-trimethylbenz (a) anthracene per 1 kg of body weight intravenously at 50 days of age. In these neonatally androgenized rats, the increase of the anogenital distance, aplasia or hypoplasia of the vagina, persistent estrus on the vaginal smears and eosinophilic substance in mammary glands were observed, with no corpus luteum formation in the ovaries, and the induction of mammary carcinomas by 7, 8, 12-trimethylbenz (a) anthracene was strongly suppressed.