Long-term effects of perinatal exposure to 5 alpha-dihydrotestosterone on normal and neoplastic mammary development in mice.

Daily subcutaneous injection of 200 microgram 5 alpha-dihydrotestosterone to SHN female mice for the first 5 days of postnatal life resulted in the stimulation of normal and neoplastic mammary development at advanced ages and it also induced the ovarian anovulatory syndrome and stimulated pituitary prolactin secretion. Daily subcutaneous injections of 1 mg 5 alpha-dihydrotestosterone to pregnant mice from day 12 to day 15 of pregnancy (prenatal treatment) had no effects on their offspring. Long-term effects of 5 alpha-DHT on normal and neoplastic mammary development in mice were generally not so marked as those observed previously with 5 beta-dihydrotestosterone which is biologically inactive in the adult.