POLYCHLORINATED BIPHENYL (PCB) EFFECTS ON HEPATIC MIXED-FUNCTION OXIDASES AND PORPHYRIA IN BIRDS .1. JAPANESE-QUAIL

1. Experiments were conducted to compare the effects of polychlorinated biphenyls (PCBs) on Japanese quail (Coturnix c. japonica). 2. Groups of six female quail were fed toxic equivalent doses estimated from rat studies of either 2,3,3'4,4'-TCB (3 mg/kg/day) or 3,3',4,4',5-PCB (0.05 mg/kg/day) and a comparable dose of 2,2',4,4',5,5'- H×CB (4 mg/kg/day) for 2 or 8 weeks. 3. Livers were assayed for ethoxyresorufin o-deethylase (EROD), 4-chlorobiphenyl hydroxylase (4-CBP), aminopyrine n-demethylase (APND) and aldrin epoxidase (AE) activity. 4. The livers were also analyzed for concentations of porphyrins by HPLC and for residues of the PCBs by GC/ECD. 5. Chronic dosing with 2,3,3',4,4'-PCB caused significant porphyrin accumulation and induction of APND, 4-CBP and EROD. 6. Quail dosed with 3,3'4,4',5-PCB for two weeks exhibited mild but significant porphyria, slight EROD and APND induction and significantly lower thymus weight. 7. Dosing with 2,2',4,4',5,5'-HxCB caused induction of APND and EROD. 8. The data show that the hepatic mixed function oxidase enzymes of the quail respond quite differently than those of rats to PCB exposure. © 1990.