Responses to Gonadotrophin in Intact and Hypophysectomized Immature Female Rats as Related to Age. ∗

Abstract

Summary

Ovarian and uterine responses of 28-, 30-, and 33-day-old normal and hypophysectomized rats to a single dosage of pregnant mare's serum (PMS) gonadotropin 24 hours prior to autopsy indicate that the intact pituitary is elaborating measurable amounts of gonadotropin during this time interval. The amount of endogenous gonadotrophin circulating in the intact 28-day animal is approximately equivalent to 10 I.U. of PMS as a reference standard. Larger equivalent quantities of gonadotrophin appear to be circulating at 30 and 33 days of age as adjudged by the end organ responses.