Effect of hypobaric hypoxia on erythrocytic glycolysis and 2,3 - DPG in rodents.

Glycolytic activity of red cells was determined in mice, rats and rabbits submitted to 4 700 and/or 6 000 m simulated altitude for variable periods of time and in controls at sea level. In all the species studied, glycolysis was found to be increased by the third week of exposure. 2,3-diphosphoglycerate (DPG) content was measured in rats submitted to simulated altitude for 4 to 66 days. A highly significant increase, which was higher at 4 700 than at 6 000 m, was found from the first days of exposure and throughout the whole experimental period. Our results are consistent with the hypothesis that variable DPG changes in different degrees of hypoxia are related to its ability to increase oxygen release to the tissues and negatively correlated with hematocrit increase. The data show that the increase in red cell glycolysis is only a temporary effect of relatively severe hypoxia, not related with changes in DPG concentration.