title: [Enzymes of the antioxidant system of rat liver during aging].
abstract: It is shown that ageing induces in rats intensification of a GSH-dependent antioxidant effect of the liver cytozole, growth of glutathione-S-transferase activity of cytozole, microsomes and mitochondria, a decrease of the NADPH generation rate in cytozole with malate and glucose-6-phosphate oxidation (the rate remaining at high level with isocytrate oxidation). It is supposed that under definite physiological conditions a lowered rate of NADPH generation in the malate dehydrogenase and glucose-6-phosphate dehydrogenase reactions in old animals may limit the efficiency of the NADPH-GSH-dependent antioxidant system of the liver cells. The peroxidase activity of cytochrome P-450 of microsomes and the glutathione reductase activity (EC 1.6.4.2) of cytozole rise in the liver of rats up to their 12 months and fall considerably with ageing. Cytochrome P-450 in the membranes of endoplasmic reticulum plays the role of an antioxidant.
mesh_terms: D000375:Aging; D000818:Animals; D000975:Antioxidants; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000254:growth & development*; D008291:Malate Dehydrogenase / Q000378:metabolism; D008297:Male; D009249:NADP / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D000975:Antioxidants; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; D008291:Malate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D005982:Glutathione Transferase; D005978:Glutathione
vernacular_title: Fermenty antioksidantnoĭ sistemy pecheni krys pri starenii.