Abstract
Female Wistar-derived rats were fed diets containing either sunflowerseed oil or tallow for 4 weeks. Rats fed the sunflowerseed oil diet had longer pentobarbitone-induced sleeping times and lower concentrations of hepatic microsomal cytochrome P-450 than rats fed the tallow diet. The addition of pentobarbitone to the drinking water of rats caused approximately 2-fold increases in the concentrations of hepatic microsomal cytochrome P-450 but did not alter the relative effect of the diets.