title: Concentration-dependent changes of PCB patterns in fish-eating mammals: structural evidence for induction of cytochrome P450.
abstract: Data sets on CB concentrations in fish-eating mammals from five laboratories were combined to test and refine a pharmacokinetic model. Clear differences in PCB patterns were observed between species. The ability to metabolize chlorobiphenyl (CB) congeners with vicinal H-atoms only in the ortho- and meta-positions and with one ortho-chlorine substituent generally increased in the order otter < cetaceans (harbor porpoise, common dolphin) < phocid seals (harbor and grey seal), but the metabolism of congeners with vicinal H-atoms in the meta- and para-positions and with two ortho-chlorines increased in the order cetaceans < seals < otter. Both categories of congeners are probably metabolized by different families of cytochrome P450 (1A and 2B) of which levels apparently differed between the cetaceans, the pinnipeds, and the otter. Within-species CB patterns differed in a concentration-dependent manner. The induction of cytochrome P450 enzymes offers the most likely explanation for this phenomenon, but starvation could have a similar effect on occasion.
authors.affiliation: Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands.
authors.forename: J P
authors.initials: JP
authors.lastname: Boon
authors.forename: J
authors.initials: J
authors.lastname: van der Meer
authors.forename: C R
authors.initials: CR
authors.lastname: Allchin
authors.forename: R J
authors.initials: RJ
authors.lastname: Law
authors.forename: J
authors.initials: J
authors.lastname: Klungsøyr
authors.forename: P E
authors.initials: PE
authors.lastname: Leonards
authors.forename: H
authors.initials: H
authors.lastname: Spliid
authors.forename: E
authors.initials: E
authors.lastname: Storr-Hansen
authors.forename: C
authors.initials: C
authors.lastname: Mckenzie
authors.forename: D E
authors.initials: DE
authors.lastname: Wells
mesh_terms: D000818:Animals; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004032:Diet; D004790:Enzyme Induction; D005399:Fishes / Q000378:metabolism*; D008322:Mammals / Q000378:metabolism*; D011078:Polychlorinated Biphenyls / Q000494:pharmacology*; D014874:Water Pollutants, Chemical / Q000494:pharmacology*
chemical_list: D014874:Water Pollutants, Chemical; D003577:Cytochrome P-450 Enzyme System; D011078:Polychlorinated Biphenyls