Facilitation of Pituitary-Induced Frog Ovulation by Progesterone in Early Fall. ∗

Abstract

Summary

In October, when Rana pipiens ovaries are notoriously insensitive to ovulatory influences, injection of one frog pituitary gland in combination with small dosages of progesterone induced nearly complete ovulation within 24 hours. Progesterone, and to a lesser extent testosterone, also exerted some ovulatory effect when injected alone.