STUDIES ON PROLAN-INDUCED OVULATION IN MIDBRAIN AND MIDBRAIN-HYPOPHYSECTOMIZED RABBITS

Abstract

When prolan (10 cc. of pregnancy urine) was injected into 16 midbrain rabbifs with hypophyses in place, ovulation occurred regularly in both large and small animals, regardless of whether short or long intervals (10 min.-6 1/2 hrs.) elapsed between the operation and injection. Its injection into midbrain-hypophysectomized large rabbits produced ovulation in all cases (8) when the interval between hypophysectomy and the injection was less than 2 hrs.; when this interval was longer, the incidence of ovulation decreased in these animals (3 out of 10). In small, midbrain-hypophysectomized rabbits (6 cases), it was impossible to cause ovulation by prolan injection even at short intervals. The possibility of the necessity of a minimal amount of hypophyseal hormone in body fluids for the occurrence of prolan-induced ovulation is discussed.