Gonadotrophic Hormone Excretion of the Pregnant Monkey (Macaca mulatto).∗

Summary The urinary excretion of gonadotrophin by pregnant Macaca mulatto, was assayed at intervals from day 22 to 179 of gestation. Hypophysectomized immature female rats were injected with concentrates equivalent to 1/4 day's output of urine. Only urine excreted between days 22 and 34 of pregnancy had a gonadotrophs action, and the action was restricted to repair of the interstitial tissue. The gonadotrophic stimulus observed in normal immature rats was comparable to that from low doses of human chorionic gonadotropin during this extremely limited period of pregnancy.