INDUCTION OF PEROXIDASE IN THE RAT UTERUS UNDER VARIOUS ENDOCRINE CONDITIONS

Abstract

Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada (Received 25 January 1977) Previous studies (Lyttle & Jellinck, 1972) have shown that an enzyme that catalyses the binding of oestradiol to protein and other high molecular weight substances in the presence of H2O2 is absent from the uteri of immature rats, but can be induced by physiological doses of oestradiol or pregnant mare serum gonadotrophin (PMSG). We now report the effect of oestradiol and PMSG administered in vivo on the induction of peroxidase in the uteri of rats under various endocrine conditions. The effects of oestradiol and progesterone on the formation of the uterine enzyme after a priming dose of oestrogen were also investigated. Uterine peroxidase was prepared from immature (26-29 days old) Holtzman rats weighing 70-90 g as described previously (Lyttle & Jellinck, 1972) and assayed by its ability to convert [4-14C] oestradiol to water-soluble products in the