[Mechanisms of the effect of cold adaptation on the resistance to hyperoxia].

Hyperoxia after 3-day exposure at 2-4 degrees C induces more obvious disturbance of metabolites in rats than each of the factors separately. Along with decreased arginase activity in the brain and liver by 23 and 32% resp., the urine content decreases as well by 36 and 37% resp. Resistance of these animals against hyperoxia is reduced. But a preliminary 45-day cold-adaptation at 2-4 degrees C leads to a considerable activation of liver arginase and to increased content of urine in brain and liver by 32 and 30%, resp. The activation of arginase--urine system preserves under hyperoxia: the cold-adapted animals prove more resistant against hyperoxia effect. The above dynamic changes seem to be one of possible unspecific biochemical mechanisms of increasing the organism resistance against effects of extreme factors.