Further investigation on ATP metabolism and red cell membrane integrity.

Among 15 enzymes PFK decreased most during preservation at 4 degrees C for 6-8 weeks, and this was prevented by the addition of adenine and inosine, but not by adenine or inosine only. PFK inactivation in hemolysate was also prevented by ATP. In order to maintain low fragility, isotonic sucrose solution was newly devised. Maltose and lactose followed and mannitol was also effective. The decrease in fragility accompanied the decrease in the cell volume and the increase of Na+, K+, H+ and Cl- in the medium. However, the filtrability of red cells was sometimes decreased in case of extremely lowered fragility. Therefore, appropriate ratios of isoosmotic sucrose (hardly permeable) and NaCl (relatively rapidly permeable) solutions must be selected for preservation of blood. Various properties in vitro of rabbit cells were well maintained and their posttransfusion viability was also prolonged when using this medium. Elimination of hypoxanthine could be achieved by hydron coated charcoal prior to transfusion.