Renal metabolism of drugs and xenobiotics

The renal cortex, outer medulla and inner medulla exhibit different profiles of drug metabolism. Mixed-function oxidase activity was present in cortex but not inner medulla. Cooxidation by prostaglandin endoperoxide synthetase was detected in inner medulla but not cortex. Both mixed-function oxidase and cooxidation were demonstrable in outer medulla. Urinary bladder carcinogens such as FANFT and benzidine and the renal carcinogen diethylstilbestrol were cooxidized by prostaglandin endoperoxide synthetase. Cooxidation could be a mechanism of activation of urinary bladder carcinogens and of nephrotoxic agents.