[Effect of hypothermia and hyperoxia on the ammonia-glutamic acid system in the brain of rats]

The content of ammonia, glutamine, dicarboxylic amino acids and GABA was studied in the brain under 1, 2, 4-fold separate and simultaneous effect of hypothermia (19-20 C) and hyperoxia (3 atm.). A two-fold hypothermia of rats is accompanied by a greater increase of ammonia in the brain than a three-fold one. The content of glutamine under two-fold cooling is unchanged and under three-fold cooling it is twice as low as compared to its content in the brain of the control rats. The content of glutamic acid decreased after two-fold hypothermia is almost unchanged by the third seance of hypothermia. The repeated actions of hyperoxia also cause a considerable increase in the ammonia content but the dynamics of changes in the content of the nitrogenous metabolic products is contary to that in animals subjected to repeated seances of hypothermia. A simultaneous combined action of hypothermia and hyperoxia produces no additive effect on the system ammonia-glutaminic acid.