INDUCTION OF OVULATION IN MICE WITH PLACENTAL GONADOTROPHINS

Abstract

SUMMARY The ovulation response was measured, by the recovery of tubal ova, in mature dioestrous albino mice after single injections of gonadotrophin, using three preparations of pregnant mares' serum (PMS) and three of human chorionic material (HCG). The dose-response lines were parallel over a limited part of the range, and similar joint action of PMS and HCG was demonstrated within these limits. Higher doses of HCG inhibited ovulation, whereas higher doses of PMS induced superovulation. The double injection technique (priming followed by ovulating injections) was examined in experiments of factorial design in immature normal and immature hypophysectomized mice. Both PMS and HCG may be used as priming or ovulatory substances in normal mice, though the equivalent doses are different for the two functions. The optimal time interval between priming and ovulatory injections, the effect of time from weaning and the response of two additional strains of mice were also examined.