Comparison of effects of C19 (androstene or androstane) steroids on serum gonadotrophin concentrations and on accessory reproductive organ weights in gonadectomized, adult male rats.

The effects of subcutaneous administration of graded doses of C19 (androstene or androstane) steroids on serum levels of LH and FSH and on weights of accessory reproductive organs in gonadectomized, adult male rats were investigated. The C19 steroids were administered during 7 days in doses of 100, 50, 25, 12.5 or 6.25 mug per 100 g body weight per day. With the amounts of steroids used, 5alpha-dihydrotestosterone and 5alpha-androstane-3alpha, 17beta-diol had a high potency in preventing the rise of serum gonadotrophin concentrations and in curbing the decrease weights of ventral prostates and seminal vesicles following orchidectomy. 5alpha-Androstane-3beta, 17beta-diol showed no such effects. Positive feedback effects on serum gonadotrophins in castrates were observed following injection of certain doses of some steroids. Effects of steroids on accessory reprosuctive organs did not always correlate with those on gonadotrophic function of the hypothalamic-pituitary unit.