Nutritional factors of microsomal enzymatic induction: influence of lipidic components of the diet.

We compared the ability of two different diets containing 6 per cent of maize oil and 6 per cent of fish oil to modify: firstly the enzyme induction by phenobarbital and secondly the phenobarbital hydroxylation by the liver either in vivo or during in vitro perfusions. The presence of fish oil in the diet increased the cyt P 450 content and the bilirubin glucuronosyl transferase activity. The two induction effects promoted by the association of the phenobarbital treatment and the eating of the fish oil were not additive and it was found that the phenobarbital induction effect was decreased by the fish oil consumption. Phenobarbital and p-hydroxyphenobarbital kinetics were different in the two groups of animals. Phenobarbital was more slowly eluted in the fish oil fed than in the maize oil fed rats while p-hydroxyphenobarbital was more slowly eluted by the fish oil-fed rat livers.