title: Studies on the pharmacokinetics and metabolism of 4-chlorodiphenyl ether in rats.
abstract: The metabolic disposition of 14C-labeled 4-chlorodiphenyl ether ([14C]4-CDE) was examined in rats following iv administration of a single dose (850 nmol/kg). [14C]4-CDE decayed rapidly from the blood since no unchanged [14C]4-CDE was detected in the blood beyond 2 hr after [14C]4-CDE administration. The dispositional kinetics of [14C]4-CDE in rats were best described by a two-compartment open pharmacokinetic model. Total radioactivity was excreted slowly from rats; about 41% and 33% of the administered dose were excreted into the urine and feces, respectively, within 1 week after chemical administration. About 5% of the total radioactivity administered to rats was excreted into the bile in 1 hr. The bulk of the radioactivity in the excreta was due to the presence of [14C]4-CDE metabolites. 14C-labeled 4'-hydroxy-4-CDE was the major metabolite and accounted for at least 90% of the radioactivity in the urine. The metabolic conversion of [14C]4-CDE to 14C-labeled 4'-hydroxy-4-CDE was corroborated by in vitro studies with liver microsomes of rats. In addition, [14C]4-CDE was converted by liver microsomes to reactive metabolites which bound irreversibly to microsomal protein. An arene oxide is suggested as the intermediate metabolite in the biotransformation of [14C]4-CDE by rats.
mesh_terms: D000818:Animals; D001646:Bile / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D055768:Halogenated Diphenyl Ethers; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D010647:Phenyl Ethers / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D055768:Halogenated Diphenyl Ethers; D010647:Phenyl Ethers; C051949:4-chlorodiphenyl ether