Effect of alpha-pinene on the mixed function microsomal oxidase system in the rat.

The microsomal fraction of the liver was studied for protein and cytochrome P 450 contents as well as for aminopyrine N-demethylase and aniline hydroxylase activity and for its butylisocyanide spectrum under the effect of alpha-pinene treatment. A moderate increase was found in the amount of microsomal protein and cytochrome P 450, a marked increase in the metabolism of both aminopyrine (substrate of type I) and aniline (substrate of type II), together with an increase in the butylisocyanide-absorption maxima of both haemoproteins involved in the reaction. Thus, alpha-pinene is a broad-spectrum enzyme inductor of the phenobarbital type, with certain quantitative differences.