Some Effects of pH and Temperature upon Normal Human Red Cell Adenosine Triphosphate

Red cell ATP levels were determined on the fresh blood of 58 normal subjects using an enzymic method. Values were obtained in the range 80 to 140 μmoles of ATP per 100 ml. of packed red cells. Conditions for obtaining reliable fresh blood ATP values are reported together with the effects of different anticoagulants. It was confirmed that red cell ATP is pH‐sensitive. Thus, at pH values below 7.6–7.7 (25° C.) it was stable but at values above this range it disappeared from the red cells. Kinetic studies of red cell ATP at different temperatures and pH values are described.