The Fate of Mestranol (17α-Ethynylestradiol-3-Methyl Ether) in the Isolated Perfused Rat Liver

Abstract

Mestranol acts as an estrogen in the organism only after demethylation by the microsomal mixed function oxidase of the liver to the hormonally active ethynylestradiol. In the isolated perfused rat liver the disappearance of [6,7-³H-] mestranol and the availability of tritiated ethynylestradiol have been studied to construct a model of the mestranol metabolism in this organ suitable for later studies on the pharmacokinetics of mestranol in humans. The fate of mestranol has been compared with the transformation of estradiol. Biliary metabolites of both mestranol and estradiol from the isolated perfused rat liver have been measured.