Metabolism of the mercapturic acid of 2,4',5-trichlorobiphenyl in rats and mice.

2,4',5-Trichloro[14C]biphenyl mercapturic acids (triCB-MA) were metabolized in part to methylsulphide, methylsulphoxide and methylsulphone metabolites after i.p., i.v. (hepatic portal vein) and p.o. administration to rats. Methylthio-triCB and triCB-MA were present in faeces and 3- and 4- methylsulphonyl-triCB (triCB-SO2CH3) were present in carcasses of all rats. Only triCB-SO2CH3 was present in lung tissue. As shown by autoradiography, radioactivity accumulated in the tracheo-bronchial mucosa of mice given either intracaecal or tail-vein injections of triCB-MA. Radioactivity extracted from the lungs of mice was shown to be present as triCB-SO2CH3.