Concentration of the major intracellular cations, water content, and potassium fluxes of wt (open bars) and tg6 (black bars) erythrocytes. (A) The intracellular sodium concentration was unaffected, whereas the potassium concentration was significantly elevated in tg6 erythrocytes. Accordingly, the water content of tg6 erythrocytes was higher compared with wt ones. (B) The increased intracellular potassium concentration was due to an increased ouabain-sensitive (active, Na/K-ATPase) transmembral potassium flux coupled with a suppression of the bumetanide-sensitive (passive, NKCC) flux. Means ± SD; *P < .05; **P < .01.