[Effect of alpha- and gamma-tocopherols on the cytochrome P-450 system in the liver of rats with E-avitaminosis. Effectiveness of liposomal forms of gamma-tocopherol].

The effects of low doses of intraperitoneally injected alpha- and gamma-tocopherols dispersed in isotonic solutions of NaCl and of liposomal gamma-tocopherol on endogenous lipid peroxidation and the cytochrome P-450 system of vitamin E-deficient rats were compared. It was found that all tocopherol preparations under study caused a twofold decrease of the lipid Schiff base concentration in the liver in comparison with tocopherol-deficient rats. However, the increase in cytochrome P-450 and b5 levels and the high functional activity of the microsomal oxidation system in the benz(a)pyrene hydroxylation reaction was induced only after liposomal gamma-tocopherol injection. It was concluded that the efficiency of the liposomal form of gamma-tocopherol can be conditioned both by preventing gamma-tocopherol oxidation in lecithin vesicles during its transport and/or by an increased liposomal gamma-tocopherol uptake by the liver from the circulating blood.