Concentration-dependent changes of PCB patterns in fish-eating mammals: structural evidence for induction of cytochrome P450.
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.
Boon
J P
JP
Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands.
van der Meer
J
J
Allchin
C R
CR
Law
R J
RJ
Klungsøyr
J
J
Leonards
P E
PE
Spliid
H
H
Storr-Hansen
E
E
Mckenzie
C
C
Wells
D E
DE
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*
D014874:Water Pollutants, Chemical; D003577:Cytochrome P-450 Enzyme System; D011078:Polychlorinated Biphenyls