Studies in red blood cell preservation. 3. A phosphate-ammonium-adenine additive solution.

The maintenance of adenosine triphosphate (ATP) in red blood cells (RBC) during storage is largely dependent on the integrity of glycolytic metabolism in the Embden-Meyerhof pathway. Meryman et al. [Transfusion 1986; 26:500-505] hypothesized that a solution that increased the surface tension of the corpuscles through hypotonic swelling might retard the development of echinocytosis and membrane loss by the shedding of exocytic vesicles. Unexpectedly, maintenance of good ATP levels and satisfactory RBC survivals were found for a long as 18 weeks. The purpose of our study was to test their observations and to explore the possible mechanisms. Equal parts of units of packed RBC were stored in the experimental preservative and, for comparison, in ADSOL. The most notable findings were ATP values at 4 weeks averaging 5.2 mumol/g Hb (130% of initial) and at 12 weeks 2.9 mumol/g Hb (73% of initial), whereas these values declined as expected in ADSOL. Mean RBC diameters and surface areas by morphometric analysis were not significantly different in the two preservatives indicating the absence of any hypotonic swelling. The morphology scores of the RBC were significantly better throughout (p less than 0.05) than in ADSOL. The shedding of exocytic hemoglobin-containing vesicles was essentially the same in both preservatives. Our data confirm the observation that ATP levels are well maintained for at least 12 weeks, but do not show any evidence that hypotonic swelling was a part of the mechanism.