Induction of monooxygenation in rainbow trout by polybrominated biphenyls: a comparative study.
Two commercial polychlorinated biphenyl mixtures (Aroclor 1254 and Aroclor 1242) and one polybrominated biphenyl mixture (FireMaster BP-6) were examined for their abilities to induce hepatic microsomal monooxygenation in rainbow trout (Salmo gairdneri). Pretreatment of rainbow trout with Aroclors 1254 and 1242 (150 mg/kg IP) resulted in an approximate 10-fold induction of arylhydrocarbon (benzo[a]pyrene) hydroxylation, ethoxycoumarin-O-deethylation and ethoxyresorufin-O-deethylation within 7 days after injection. These enzyme activities remained elevated above control values for at least 2-3 weeks. Administration of FireMaster BP-6 (150 mg/kg IP) also resulted in an induction of several monooxygenase activities. Arylhydrocarbon (benzo[a]pyrene) hydroxylation, ethoxycoumarin-O-deethylation and ethoxyresorufin-O-deethylation were increased by 6-, 3,- and 25-fold, respectively. Only the latter two activities remained elevated two weeks post-injection. Ethylmorphine-N-demethylation was unaffected by the polyhalogenated biphenyls. Significant increases in P-450 hemoprotein were not observed after pretreatment with any of the polyhalogenated biphenyls studied.
D000818:Animals; D001140:Aroclors / Q000378:metabolism*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004463:Ecology; D004790:Enzyme Induction; D005399:Fishes; D005411:Flame Retardants / Q000633:toxicity; D008862:Microsomes, Liver / Q000201:enzymology*; D010088:Oxidoreductases / Q000096:biosynthesis*; D011075:Polybrominated Biphenyls / Q000494:pharmacology* / Q000633:toxicity; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D013053:Spectrophotometry; D013268:Stimulation, Chemical
D001140:Aroclors; D001713:Biphenyl Compounds; D005411:Flame Retardants; D011075:Polybrominated Biphenyls; D011078:Polychlorinated Biphenyls; D010088:Oxidoreductases