TEMPORAL ASPECTS OF INDUCTION OF HEPATIC CYTOCHROME-P450 1A AND CONJUGATING ENZYMES IN THE VIVIPAROUS BLENNY (ZOARCES-VIVIPARUS) TREATED WITH PETROLEUM-HYDROCARBONS

The heavy gas oil fraction of distilled North Sea crude oil was intraperitoneally injected into the marine teleost viviparous blenny (Zoarces viviparus). The effects were compared with those of the model inducer, beta-naphthoflavone (beta-NF), on the hepatic cytochrome P450 1 A (P450 1 A or CYP IA) system and on conjugating enzymes in a time course study over 14 days. The injection of heavy gas oil resulted in temporal responses in P450 IA protein content and P450 1 A catalytic activity similar to those obtained with beta-NF, although differences existed in terms of their effects on CYP1A1 mRNA levels and on the total P450 content. In contrast to beta-NF, heavy gas oil had no effect on UDP-glucuronosyltransferase, glutathione S-transferase and glutathione reductase activities. GC-MS analyses of pooled bile, the major route of excretion of organic hydrocarbons, of viviparous blenny treated with heavy gas oil revealed that besides naphthalene the bile also contained polycyclic aromatic hydrocarbons (PAHs) such as phenanthrenes, anthracene, pyrenes, fluoranthene, benzo(a)anthracene and chrysene. None of these compounds were detected in bile from control fish, with the only exception of 3-methylphenanthrene. This study indicates the usefulness of the P450 IA system in the viviparous blenny as a sensitive biomarker in monitoring studies in petroleum oil contaminated areas in Northern Europe.