TEMPORAL INDUCTION OF CYTOCHROME-P450 1A IN THE MIRROR CARP (CYPRINUS-CARPIO) AFTER ADMINISTRATION OF SEVERAL POLYCYCLIC AROMATIC-HYDROCARBONS

High inductions of 7-ethoxyresorufin O-deethylation (EROD) activities, cytochrome P450 1A protein levels (P450 1A), and total cytochrome P45 0 content (P450) were observed 1, 2, 5, and 14 d after a single i.p. i njection of 99.5 mumol/kg benzo[a]pyrene (BaP) and chrysene (Chrys). T he highest inductions in EROD activities and P450 IA protein levels we re seen 2 d after treatment, approximately 35- and 11-fold relative to the controls. Less pronounced increases of EROD activities and P450 I A protein levels, approximately 3- to 10-fold and 6-fold, respectively , were observed after treatment with equimolar concentrations of fluor anthene (Fluor) and pyrene (Pyr). Benzo[ghi]perylene (BghiP) and the c arrier dimethyl sulfoxide (DMSO) did not affect these parameters. The highest concentrations of PAHs in the liver, equivalent to 2 to 25% of the dose, were found 1 or 2 d after treatment. The highest percentage of the dose in the liver was observed for Chrys, followed by BghiP, B aP, Fluor, and Pyr. Poor correlations were found between hepatic conce ntrations of PAHs and P450 1A increases, which might be attributed to the rapid metabolism of these compounds.