Effect of Polycyclic Aromatic Hydrocarbons on Hepatic Microsomal Enzymes and Disposition of Methylnaphthalene in Rainbow Trout in vivo

Abstract

1. The effects of 3-methylcholanthrene, 2,3-benzanthracene and β-naphthoflavone on xenobiotic metabolism in rainbow trout were studied.

2. These three polycyclic aromatic hydrocarbons increase hepatic arylhydrocarbon (benzo[a]pyrene) hydroxylase activity without altering glucuronyl transferase activity.

3. All three polycyclic aromatic hydrocarbons increased hepatic microsomal cytochrome P-450 levels by approximately 50%.

4. Pretreatment of trout with 2,3-benzanthracene resulted in an increase in the metabolism and biliary excretion of 2-methylnaphthalene in vivo.

5. These studies demonstrate that the induction of mono-oxygenation by polycyclic aromatic hydrocarbons can result in significant effects upon the metabolism and excretion of xenobiotics by fish in vivo.