SUPEROVULATION IN THE IMMATURE RAT FOLLOWING TREATMENT WITH PMS ALONE AND INHIBITION OF PMS-INDUCED OVULATION

Abstract

SUMMARY Superovulation can be induced in the immature rat by PMS alone or PMS followed by HCG. Treatment with PMS alone caused an initial average response of 2·8 ova at an age of 20 days and a maximum average response of 70·8 ova at age 28. Treatment with PMS and HCG resulted in an initial average response of 0·3 ova at age 18 days and an average maximum of 61 ova at 22 days of age. A marked drop to approximately 8–10 ova was noted at 45 days of age following both types of treatment. Hypophysectomy revealed that the pituitary gland was necessary for the release of ova following injection of PMS alone. Removal of the pituitary gland as late as 52 hr. after injection of PMS prevented ovulation. Inhibition of ovulation by treatment with dibenamine, SKF-501, atropine and 'Nembutal' following injection of PMS alone led to the concept that superovulation following PMS involves a neural link that is responsible for the endogenous release of LH.