[Lipid peroxidation in the postnuclear and microsomal fractions of rat liver homogenates upon aging].

The rate of lipid peroxidation in the postnuclear fraction of rat liver homogenate determined by malonic dialdehyde appearance decreases upon ageing. This is due to a decrease in the enzymatic lipid peroxidation in microsomes and to an increase in the NADPH-dependent (antioxidant) effect of the soluble fraction of rat liver cells. The latter effect is mediated by thiols and is presumably caused by the increase in the glutathione peroxidase activity upon ageing.