Hemoglobin function in stored blood. VI. The effect of phosphate on erythrocyte ATP and 2,3-DPG.

Abstract

Inorganic phosphate, known to stimulate erythrocyte glycolysis, is present in one of the preservatives for blood storage, citrate–phosphate–dextrose (CPD), but not the other, acid-citrate-dextrose (ACD). Both ACD and CPD were developed before it was known that erythrocyte 2,3-diphosphoglycerate (2,3-DPG) was necessary for normal hemoglobin function. The phosphate in CPD gives a final concentration of 2 mM, which is less than the concentrations originally used to study the phosphate effect. Therefore, the present study was designed to see whether higher concentrations of phosphate would better maintain erythrocyte concentrations of 2,3-DPG during blood storage. For maintaining 2,3-DPG, 2 mM phosphate was the best; however, 5 mM phosphate was nearly as good. Ten, 15, and 20 mM phosphate were progressively worse. Also, there was very little difference between 2 and 5 mM phosphate with respect to ATP, and the highest phosphate concentration was the worst.