Erythrocyte adenosine triphosphate depletion during voluntary hyperventilation

Chronic hypophosphatemia in humans is associated with a slow depletion of adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) in erythrocytes, combined with shape alteration, impaired deformability, and viability of the cells. Likewise, incubation of erythrocytes in alkaline solution is associated with ATP depletion. Since in hyperventilation both hypophosphatemia and alkalosis are present, we have investigated red cell organic phosphates, shape, deformability, and osmotic fragility before, during, and after 20 min of voluntary hyperventilation. On the average, red cell ATP decreased by 42%, the blood pH increased by 0.2 units, and plasma inorganic phosphorus decreased by 46% compared with the initial values. Red cell 2,3-DPG, shape, deformability, and osmotic fragility remained unchanged. After the end of hyperventilation ATP increased rapidly to control values in parallel with the normalization of the blood pH, whereas inorganic plasma phosphorus remained at the low level observed during hyperventilation. It is concluded that the combined effects of hypophosphatemia and alkalosis in acute hyperventilation lead to an isolated fall of red cell ATP, which occurs as rapid as after total inhibition of red cell glycolysis in vitro.