Sodium and potassium changes in blood bank stored human erythrocytes.

Storage of red cells for three weeks at 4 C under blood bank conditions resulted in a rise in intracellular Na+ and a fall in intracellular K+ with concomitant opposite changes in Na+ and K+ levels in the suspending plasma. A decline in red blood cell ATP during the storage period did not appear to be contributing to the changes. Increasing red blood cell ATP to levels 2 to 3 times normal did not prevent the cation changes from occurring. When assayed at 37 C in the presence of added Mg++, ouabain-sensitive membrane ATPase activity and kinetics of activation by Na+ were unaffected by the three week period of cold storage. However, when assayed at 4 C without added Mg++, simulating the conditions of storage, ATPase activity was negligible. Sodium and potassium did not change when red blood cells with normal ATP content were stored at 20 to 24 C even in the absence of added Mg++. Thus, a major cause for the development of cation changes in the red blood cell during blood bank storage in the temperature which inhibits membrane ATPase, allowing cations to leak unopposed into and out of the red blood cells.