Hemoglobin Function in Stored Blood

Abstract

An optimal pH was sought to maintain hemoglobin function, ATP, and red blood cell viability during liquid storage under blood banking conditions. Ten units of blood from normal volunteers were subjected to an automated analytical system for determining concentrations of 2,3‐DPG and ATP. Each unit was split during donation into five parts containing citrate—dextrose solutions of pH 5.0, 5.5, 6.0, 6.5, and 7.0. Significant differences at the 95 per cent level were based on the paired t‐test. In addition, osmotic fragility and methylene blue uptake were determined to assess their possible usefulness as indicators of either red blood cell viability or ATP. With pH 5.0 preservative 2,3‐DPG fell from day 0 to day 3, with pH 5.0 and 5.5 preservatives from day 3 to day 7, and from day 7 to day 14 in all pH groups. A plot of 2,3‐DPG versus hydrogen ion concentration showed that in excess of 1 × 10−7hydrogen ion, corresponding to pH 7.0, 2,3‐DPG concentration falls at a rapid rate. From 2,3‐DPG and ATP data, a preservative with pH higher than 5.5 would seem to be optimal for maintaining hemoglobin function and red blood cell viability, but adenine may be needed to maintain adequate ATP levels.