The physiological and pharmacological roles of cytochrome P450 isoenzymes

The cytochrome P450 isoenzymes are a superfamily of haemoprotein enzymes th at catalyse the metabolism of a large number of endogenous and exogenous co mpounds. Recently, the cytochrome isoenzymes have been shown to be importan t in the synthesis of steroid hormones and bile acids, the arachidonic acid cascade and in central nervous function. These enzymes are a major determi nant of the pharmacokinetic behaviour of numerous drugs. Furthermore, alter ations in cytochrome P450 activity have been implicated in some diseases.