THE INTERRELATIONSHIP OF THE PITUITARY SEX HORMONES IN OVULATION, CORPUS LUTEUM FORMATION, AND CORPUS LUTEUM SECRETION IN THE HYPOPHYSECTOMIZED RABBIT1

Abstract

Hypophysectomy in the rabbit resulted in a progressive loss of function of the corpus luteum in about 5 days; large, medium and small follicles became atretic and degenerated by the end of 2, 15 and 30 days respectively. Primary follicles persisted for 90-100 days. Vacuolar degeneration of the interstitial cells began at 30 days and was completed by 55 days. Follicle-stimulating extracts of the pituitary arrested follicular atresia and when injected within 3 days after hypophysectomy prevented it. Ovulation. of hypophysectomized rabbits by a single intraven. injection of pituitary extracts was followed within a few days by atrophy of the granulosa with little or no development of lutein tissue. When ovulation was followed by treatment with F.S.H. extracts alone the ruptured follicle failed to develop into lutein tissue and the uteri remained in an oestrous condition. However, after administration of L.H. or a combination of the 2 hormones functional corpora lutea were formed aa shown by a maximal pseudopregnancy reaction in the uterus.