THE EFFECT OF PREGNANT MARE SERUM GONADOTROPHIN AND HUMAN CHORIONIC GONADOTROPHIN ON RAT OVARIAN ASCORBIC ACID AND CHOLESTEROL

Abstract

SUMMARY The effect of the administration of 50 i.u. pregnant mare serum gonadotrophin (PMSG), followed 72 hr. later by 25 i.u. human chorionic gonadotrophin (HCG), on ovarian weight, ascorbic acid and cholesterol has been investigated in rats of the Wistar strain bred in a closed colony. In the ovarian ascorbic acid depletion (OAAD) test for luteinizing hormone (LH) the bioassay is generally carried out from 5 to 9 days after the administration of HCG. The present investigation has shown that at this time ovarian ascorbic acid levels in untreated animals are in the same range as in rats pretreated with PMSG and HCG. The reasons for conducting the ovarian cholesterol depletion (OCD) test for LH on the 11th day after treatment with HCG are discussed. It is concluded that in the strain of animal used assays conducted before this time are likely to be unsatisfactory. It is postulated that the main function of the pretreatment procedure in both assay methods is to produce a large amount of highly reactive ovarian tissue which is readily responsive to the administration of LH.