[Lipid peroxidation during extreme hyperthermia of rats].

The influence of extremal cryoeffects on the state of prooxidant and antioxidant systems in the blood serum and heart tissues was studied in young and old rats. It is shown that kinematic parameters of chemiluminescence after cold effects are less expressed in the blood serum of old animals than in young ones. The level of TBA-active products in the blood of young rats was lower than in old ones. After the 6th and 9th cold effect the content of TBA-active products in old animal appoaches such indices in young animals. Three weeks after the cold effects the content of TBA-active products in the myocardium of old rats corresponded to control indices, while in the young ones they were considerably lower. The fermentative link state was investigated in the antioxidant protection system. After the extremal cryoeffects glutathione reductase and glutathione peroxidase activity in old animals approaches its indices in intact rats, while catalase activity increases. Three weeks after cryoeffects one can observe a stable increase of fermentative activity of heart tissues both in old and young animals compared with the control that can evidence for the increase of the organism cold resistance.