Hepatic biotransformation in the buzzard (Buteo buteo) and the Japanese quail (Coturnix coturnix): Effect of PCBs

Abstract 1. Hepatic biotransformation was studied in microsomal (cytochrome P-450-dependent monooxygenase activities) and cytosolic (glutathione S -transferase activitiesz) fractions from Japanese quail ( Coturnix coturnix ) and buzzard ( Buteo buteo ). 2. Monooxygenase activities were not very different apart from a high 7-ethoxycoumarin de-ethylase activity in quail as compared to buzzard. 3. Glutathione S -transferase activities were higher in quail than in buzzard. 4. DP 5 (a commercial mixture of PCBs containing 50% chlorine) produced a marked increase in monooxygenase activity from quail liver. In contrast, no induction was found in buzzard under the same conditions. Glutathione S -transferase activities were not modified in both species.