title: Comparative metabolism of polychlorinated biphenyls and tissue distribution of persistent metabolites in rats, hamsters, and Guinea pigs.
abstract: The present study was performed to compare the metabolite profiles of polychlorinated biphenyls (PCBs) in the liver and serum of rats, hamsters, and guinea pigs after exposure to a PCB mixture, Kanechlor 500 (100 mg/kg, i.p.). The percentage of contribution of major PCB residues in the liver 5 days after exposure indicated that nonplanar PCBs with 2,4- or 2,3,4-chlorine substitution were more abundant in the liver in the order rats (43% of total PCBs) > hamsters (20%) > guinea pigs (11%), whereas coplanar PCBs with 4-, 3,4-, or 3,4,5-chlorine substitution were predominant in guinea pigs (61%), followed by hamsters and rats (both 26%). The hepatic concentrations of methylsulfonyl metabolites (MeSO(2)-CBs) were higher in the order guinea pigs > rats > hamsters. Whereas hamsters formed minute amounts of MeSO(2)-CBs from 2,5-dichloro-substituted PCBs, guinea pigs formed higher levels of meta-MeSO(2)-CBs derived from 2,3,6-trichloro-substituted PCBs. In contrast, the serum concentrations of phenolic PCBs were higher in the order hamsters > rats > guinea pigs. Metabolites were predominated by 4-OH-2,3,5,3',4'-pentaCB (89% contribution) for rats, 3-OH-2,4,5,2',4'-pentaCB (56%) for guinea pigs, and dihydroxylated metabolites (39%) for hamsters. The reduced elimination of coplanar PCBs and the specific distribution of MeSO(2)- and phenolic PCBs may have implications for the differences in sensitivity to PCB toxicity among rats, guinea pigs, and hamsters.
authors.affiliation: Daiichi College of Pharmaceutical Sciences, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan. ko-ichi@ka2.so-net.ne.jp
authors.forename: Koichi
authors.initials: K
authors.lastname: Haraguchi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Koga
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Kato
mesh_terms: D000818:Animals; D006224:Cricetinae; D004785:Environmental Pollutants / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D006168:Guinea Pigs; D008099:Liver / Q000378:metabolism; D008297:Male; D008647:Mesocricetus; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D013045:Species Specificity; D014018:Tissue Distribution
chemical_list: D004785:Environmental Pollutants; C477388:KC 500; D011078:Polychlorinated Biphenyls