[The role of peroxidation processes and antioxidant protection in nitrite-induced hypoxia and its correction with vitamins].

Different doses of sodium nitrite were studied for their action in acute and chronic experiments on rats. Nitrite (NaNO2) hypoxia in rats was simulated to show how the methemoglobin (MtHb) level in blood depends on NaNO2 doses and the method of introduction. Lethal and sublethal doses of NaNO2 (50% of MtHb and more) promoted a decrease of lipid peroxidation (LP) in the liver microsomes, while the average and easy level of hypoxia activated it. Introduction of NaNO2 has led to dose-dependent activation of superoxide dismutase (SOD) in the liver, blood and heart tissues as well as to disturbances in the DNA structure. An average level (40 mg NaNO2 per kg of rat weight daily during one month) of chronic nitrite hypoxia has led to the same changes of metabolism as acute one. Vitamin E normalized LP, but not the MtHb level.