EFFECT OF AT-125 ON THE METABOLISM OF PROPACHLOR AND THE GLUTATHIONE CONJUGATES OF PROPACHLOR AND BROMOBENZENE IN RAT

1. Dosing rats with the gamma-glutamyl-transpeptidase inhibitor AT-125 results in the excretion of free glutathione in the urine of rat: thi s treatment did not lead to the excretion of glutathione conjugates of orally dosed xenobiotics, neither did AT-125 increase the biliary exc retion of glutathione conjugates. 2. Dosing rat with AT-125 prior to d osing with 2-chloro-N-isopropylacetanilide decreased the excretion of 2-methylsulphonylacetanilide metabolites from 23% of the dose to <0.5% . 3. We conclude that glutathione and glutathione-xenobiotic conjugate s are probably not processed in vivo by the same pathway, and that AT- 125 can alter the in vivo transport of mercapturic acid pathway metabo lites.