Comparative biotransformation studies of MeIQx and PhIP in animal models and humans

MeIQx and PhIP are putative carcinogenic heterocyclic amines formed during the cooking of meat and fish. Using accelerator mass spectrometry, we have investigated the metabolism and macromolecule binding of C-14-labelled MeIQ x and PhIP in human cancer patients compared to the rat. Following oral adm inistration of MeIQx and PhIP, more DNA adducts were formed in human colon tissue compared with rats. Differences were also observed between rats and humans in the metabolite profile and urine excretion for these compounds. T hese results suggest humans metabolise heterocyclic amines differently to l aboratory rodents and question their use as models of human risk. (C) 1999 Published by Elsevier Science Ireland Ltd.