EFFECT OF IRRADIATION ON RED-CELL CATION CONTENT AND TRANSPORT

The effect of irradiation on red cell (RBC) cation content and membrane transport was studied. When units of RBCs collected in AS-1 (n = 8) were exposed to radiation (2000 cGy) and then stored at 4-degrees-C, there was a significant increase in external K and internal Na and a decrease in internal K relative to control units (n = 3). Similar changes in internal cation contents were noted for RBCs collected in CPD; because of the higher hematocrit, the external K concentration was higher than that in AS-1-collected RBCs. Cellular K loss and Na gain were balanced, and the total cation content remained constant; however, both control and irradiated cells swelled over time as a consequence of the decreased pH and 2,3 DPG content. These changes in volume and cation content were reversed when the cells were incubated at 37-degrees-C. A specific effect of radiation on the Na-K pump and Na-K-Cl and K-Cl cotransport systems was ruled out, because no significant differences between irradiated cells and controls were found. These data indicate that radiation induces an increased permeability to Na and K on the part of the RBC membrane lipid bilayer and that this increase is balanced and reversible.