Evidence for androgen participation in induced ovulation in immature rats.

Rabbit antiserum to testosterone injected intravenously (iv) together with 10 IU human chorionic gonadotropin (hCG) markedly reduced the number of tubal ova in intact or hypophysectomized immature rats primed with 5 IU pregnant mare's serum gonadotropin. Normal rabbit serum (NRS) injected instead of the antiserum resulted in a normal complement of ovulated ova. Ten microgram of testosterone or 5alpha-dihydrotestosterone dissolved in NRS administered iv 1 h after simultaneous injection of hCG and antiserum to progesterone (anti-P) restored ovulation that would otherwise have been blocked by anti-P, with a comparable number of ova to control animals not given anti-P. The results indicate active participation of androgen in induced ovulation in immature rats.