title: Effect of polybrominated biphenyls on drug metabolizing enzymes in different tissues of C57 mice.
abstract: Polybrominated biphenyls (PBBs) are structurally very close to polychlorinated biphenyls (PCBs) which are known to be potent inducers of xenobiotic biotransformation reactions. We have studied the effects of 2 industrial PBB-mixtures, "hexabromobiphenyl" (HBB) and "octabromobiphenyl" (OBB), on enzymes catalyzing drug hydroxylation, epoxide hydration, and conjugation reactions in different tissues of C57 mice. The enzyme activities were measured 10 days after a single i.p. injection of PBBs (75 mg/kg). HBB enhanced the activities of hepatic AHH (1.9-fold), ethoxycoumarin deethylase (5.7-fold), epoxide hydratase (1.5-fold), glutathione S-transferase (1.7-fold) and UDP-glucuronosyltransferase (1.5-fold). In the kidney HBB enhanced the activity of UDP-blucuronosyltransferase 1.5-fold. OBB caused in increase in the activities of liver AHH (1.5-fold), ethoxycoumarin deethylase (2.4-fold) and glutathione S-transferase (1.4-fold). A slight increase was also seen in the activity of UDP-glucuronosyltransferase in digitoninactivated liver microsomes of OBB-treated mice. In the kidney OBB caused a slight but statistically significant decrease in glutathione S-transferase activity. Intraperitoneally injected bromobiphenyls had no effects on these drug metabolizing enzymes in the lung of C57 mice. These results were similar to the effects caused by a mixture of PCBs.
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D001713:Biphenyl Compounds / Q000494:pharmacology*; D004851:Epoxide Hydrolases / Q000378:metabolism; D014453:Glucuronosyltransferase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D010088:Oxidoreductases / Q000378:metabolism*; D011075:Polybrominated Biphenyls / Q000494:pharmacology*
chemical_list: D001713:Biphenyl Compounds; D011075:Polybrominated Biphenyls; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; D001189:Aryl Hydrocarbon Hydroxylases; D014453:Glucuronosyltransferase; D005982:Glutathione Transferase; D004851:Epoxide Hydrolases