Induction of hepatic cytochrome P-450IA1 in pigeons treated in vivo with Aroclor 1254, a commercial mixture of polychlorinated biphenyls (PCBs).
1. Treatment with a commercial mixture of polychlorinated biphenyls (PCBs) resulted in highly significant increases in pigeon hepatic microsomal proteins (100-fold), cytochrome P-450 (11-fold), cytochrome b5 (7-fold), NADPH-cytochrome c-(P450) reductase (7-fold), ethoxycoumarin-O-deethylation (9-fold), aldrin epoxidase (22-fold), ethoxyresorufin-O-deethylation (48-fold), N-demethylation of dimethylnitrosamine (28-fold) but not of lauric acid 12-hydroxylation. 2. SDS-PAGE analysis of pigeon hepatic microsomal proteins induced by Aroclor 1254 suggested highly significant increases in the density of staining in bands of estimated Mr 51-52 kD, 54-54.5 kD, 57-58 kD, 59-60 kD and of 77.5-78.5 kD. 3. The induction of cytochrome P-450IA1 was confirmed by Western immunoblotting using the monoclonal antibodies MAB 1-12-3 and MAB 1-8-4. 4. There was agreement between the 8-fold increase in cytochrome P-450IA1 increased staining of microsomal proteins, as judged by SDS-PAGE, and the 24-fold increase in the amount of protein that reacted with the monoclonal antibodies MAB 1-12-3 and MAB 1-8-4, as judged by Western immunoblotting. 5. It is concluded that treatment with a commercial PCB mixture resulted in the induction of several isoforms of pigeon hepatic cytochrome P-450 in a fashion that is likely to be similar to that reported for mammals.
Department of Biochemistry and Physiology, School of Animal and Microbial Science, University of Reading, U.K.
J T
JT
Borlakoglu
J
J
Stegeman
R R
RR
Dils
D000818:Animals; D000911:Antibodies, Monoclonal; D001140:Aroclors / Q000494:pharmacology*; D015153:Blotting, Western; D020111:Chlorodiphenyl (54% Chlorine); D010856:Columbidae / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D003720:Densitometry; D004591:Electrophoresis, Polyacrylamide Gel; D004790:Enzyme Induction; D005260:Female; D005659:Fungicides, Industrial / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology; D011078:Polychlorinated Biphenyls / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D000911:Antibodies, Monoclonal; D001140:Aroclors; D005659:Fungicides, Industrial; D007093:Imidazoles; D020111:Chlorodiphenyl (54% Chlorine); D003577:Cytochrome P-450 Enzyme System; C045362:prochloraz; D011078:Polychlorinated Biphenyls