[Nutritional lipidic factors of enzymatic phenobarbital induction in the rat. Effects of quantitative and qualitative composition of dietary lipids (author's transl)].

Diets containing increasing amounts of corn oil (0%, 1,5%, 3%, 4,5%, 6%), diets containing a same quantity (6%) of differents fats (corn oil, coconut oil, fish oil) and one free fat diet containing squalen (1,5%) were fed to rats. The UDP glucuronosyl transferase (UDPGT) activity of hepatic homogenate and cytochrome P 450 concentration of hepatic microsomal fractions were measured without or after phenobarbital treatment. 1. Presence of dietary lipids generally gives a moderate increase of these parameters, but the effect of fish oil is higher than of other fats. 2. With the phenobarbital treatment the induction of hepatic cyt P 450 and UDPGT is higher in the animals fed dietary fats than in animals fed free fat diets. However this difference is more important in the rats fed fish oil, less important with coconut oil and the lowest with corn oil. 3. The addition of squalen in the diet did not give variations of cyt P 450 hepatic concentration and UDPGT hepatic activity. The inducting effect of phenobarbital on microsomal cyt P 450 is unchanged but significantly enhanced in the case of hepatic UDPGT.