REGULATION OF THE CYTOCHROME-P450 ENZYME-SYSTEM IN FISH

The cytochrome P450 monooxygenase system metabolizes a large number of xenobiotic compounds including many environmental pollutants. This metabolism can lead to detoxification, or in some cases, activation to reactive intermediates with toxic and carcinogenic effects. Among animals living in the aquatic environment the cytochromes P450 have been studied best in fish. The catalytic properties and factors regulating their activity have been an important field for aquatic toxicology investigations. A major concern is the mechanisms associated with the induction of cytochrome P450 by organic hydrocarbons. Several variables such as development stage, sex, and ambient temperature may influence the P450 enzyme system and its inductive response. The objective of this review is to discuss recent progress in studies of regulation of the cytochrome P450 enzyme system in fish.