Abstract
During acute exposure to high altitude (2 hours) the red cell metabolism is altered. A pH-induced increase in phosphofructokinase activity together with a decrease in the level of the monophosphoglycerates are the most prominent features of the changes. Despite the increase in pH, the level of 2,3-diphos-phoglycerate is not altered, probably because of a reduction in the concentration of inorganic phosphate. Besides 2,3-DPG neither ATP, ADP, lactate, or pyruvate levels are changed significantly during exposure of this duration. The results are interpreted as being due to a combined effect of alkalosis and a decrease in the concentration of inorganic phosphate.