Effect of dietary rapeseed oil on hepatic hexobarbital metabolism in mice

The effect of dietary rapeseed oil (RSO) on hepatic hexobarbital metabolism has been studied in short-term experiments in mice by measuring both the activity of mixed function oxidase system in microsomal preparations in vitro and the in vivo hexobarbital-induced sleeping time. Moreover, the fatty acid pattern of liver tissue, with particular regard to erucic and gadoleic acids, was analyzed gas-chromatographically. The hexobarbital metabolism in young RSO-fed mice (RSO containing 52 % of erucic acid and 7.4 % of gadoleic acid; 50 cal% for 3 days) is lower by about 44 % than in controls treated in the same way with peanut oil, independently of sex. RSO did not have a statistically significant effect on hexobarbital metabolism in adult animals of both sexes. As to the dose-response study, the prolongation of the hexobarbital-induced sleeping time in young male mice is statistically significant when fed with 30 cal% in RSO for 3 days, while it is not more statistically significant in mice fed 15 cal% in RSO. In RSO mice (50 cal%) erucic and gadoleic acid account both for about 10 % of the total fatty acids in the liver tissue, while they are quite absent in controls. It causes a relative deficiency of linoleic and arachidonic acids, known to be essential for synthesis and maintenance of the membranes supporting hepatic microsomal enzymes responsible for the metabolism of some drugs.