MODULATION OF CYTOCHROME-P450 1A IN SEA BASS LIVER BY MODEL SUBSTANCES AND SEAWATER EXTRACTS

1. Immunochemical and catalytic assays for cytochrome P450 1A inductio n in liver of sea bass Dicentrarchus labrax treated with different mod el substances and organic seawater extracts have been performed. 2. Et hoxyresorufin-O-deethylase (EROD) activities in fish liver were elevat ed by Arochlor 1254 (Are), 3-methylcholanthrene (MC) and beta-naphtofl avone (beta NF), but not by phenobarbital (PB) treatment. 3. Elevated levels of P450; 1A protein followed;ed by induction of EROD activity w ere detected only in beta NF treated fish. 4. Treatment of fish with o rganic seawater extracts revealed that there is no simple correlation between EROD activities and its catalyst P450 1A level. Seawater extra cts are mixtures of chemicals that have the ability to suppress the le vels of P450 1A and/or to inhibit EROD activity. (C) 1998 Elsevier Sci ence B.V.