THE METABOLISM OF CORTISOL BY HUMAN EXTRA-HEPATIC TISSUES

Abstract

SUMMARY: The extra-hepatic metabolism of cortisol in man has been studied in vitro by incubation of [4-¹⁴C]cortisol with tissue slices. Kidney tissue was the most active, followed by prostate; thyroid, skeletal muscle and synovial membrane were much less effective. Cortisone was quantitatively the predominant metabolite but C-20-reduced derivatives of cortisol and cortisone were also present. There was evidence for the oxidation of the side chain by kidney and prostate, but no ring A-reduced compounds were found. Kidney slices did not reduce the 11-oxo group of cortisone but this reaction proceeded readily with liver slices. Some evidence for extra-hepatic metabolism of cortisol in vivo by the tissues of the forearm was obtained by infusing [4-¹⁴C]cortisol into the brachial artery.