[Effect of the cholesterol and protein diet on cytochrome P-450 dependent monooxygenase activity]

The effect of cholesterol and protein diet on mixed-function oxidase activity and desaturation of fatty acids were studid as well as phenobarbital inducibility of those parameters. Investigations were carried out on Wistar adult male rats. The animals were on the cholesterol (0.25%) and protein (32%) diet for 45 days. Cytochrome P-450 and cytochrome b5 contents, NADPH-cytochrome P-450 reductase, NADH-cytochrome b5 reductase, aniline hydroxylase and 4-aminopyrine N-demethylase activities were measured in a hepatic microsomal fraction. The cholesterol diet exerted a negative effect on all parameters except NADH-cytohrom b5 reductase. The protein diet did not change the activity or levels of enzymes under study. The only exception applied to induction of NADH-cytochrome b5 reductase and 4-aminopyrine N-demethylase activities. Simultaneous treatment with phenobarbital had a heterogenous effect depending on the type of diet and parameters examined.