[Prevention of the activation of lipid peroxidation and of damage to the myocardial antioxidant systems in stress and experimental infarct].

It was shown that the multifold increase of intermediate products of lipids peroxidation, their hydroperoxides, and terminate products of this process, Shiff's bases, occurred in rats with experimental myocardial infarction both in the ischemic and in nonischemic zones. Simultaneously the activity of antioxidant enzymic systems reduced in the myocardium; the superoxydismutase and catalase activities decreased insignificantly and the glutatione peroxidase activity was 2-fold decreased. The preliminary adaptation of the animals to the periodic action of hypoxia itself did not influence the antioxidant systems of the organism but it significantly decreased the accumulation of the lipids peroxidation products and the size of ischemic necrosis. It is suggested that the protective effect of the adaptation of hypoxia during the heart ischemic damage is realized not by the increase of the antioxidant systems activity but by the change in the membrane lipid composition.