[Status of cell membrane enzymes in hypoxia and the protective effect of pyrazidole]

The influence of hypobaric hypoxia simulating the altitude of 9000 m above the sea level during 3 hours on the stability of erythrocyte, lysosomal, and mitochondrial membranes, has been studied. The increase in extra erythrocyte hemoglobin and free iron concentrations and the total peroxidase activity in blood plasma testify to increased permeability of the erythrocyte membrane. An increase in the free activity of acid peptide hydrolases in the soluble fraction and their activity decrease in the lysosomal membrane. The mitochondrial monoamine oxidase activity in the soluble fraction of the brain is suggestive of structural damages to the mitochondrial membrane. Preliminary administration of pyrasidol prior to hypoxia has a stabilizing effect on all types of membrane structures.