Opiate-specific effects on mRNA and catalytic activity of a hepatic cytochrome P450 isozyme

Behavioural and biochemical endocrine effects, such as suppression of testosterone plasma levels and decreased libido, occur both in humans and in animals following exposure to opiates (1; 2). Some of the biochemical effects may be associated with perturbations in the cytochrome P450 (CYP) enzyme superfamily. This enzyme system encompasses a large number of hemoproteins that catalyze the oxidation of numerous xenobiotics including drugs such as opiates, and various endogenous substrates, e.g. steroids and fatty acids (3). The development of some of the enzymes of this system are age-dependent and tissue-specific