[Pyridine nucleotide content in the brain and myocardium of rats under combined effect of hypercapnia, hypoxia and cooling].

In experiments with rats, subjected to single and repeated simultaneous effect of hypercapnia, hypoxia and cooling, contents of pyridine nucleotides (NAD, NADP, NAD-H2 and NADP-H2) and macroergic substances were studied and also the activity of dehydrogenases of the pentose pathway was determined in brain and myocardium. In brain NADP was not practically determined and in heart its content was increased after the first and the second treatments. Content of NADP-H2 was distinctly decreased in both tissues after the single treatment. NAD was not altered in the tissues in all the periods studied. The amount of NAD-H2 was decreased in brain after the single treatment and it was increased in myocardium after the repeated one. In the activity of dehydrogenases marked alterations were not observed. Total macroergic substances were not altered in brain after the single treatment and after the repeated one they were increased mainly due to the ATP increase. In myocardium total macroergic substances were decreased after the both treatments.