Volume-stimulated KCC fluxes in SS, SC, and AA RBCs. Ouabain- and bumetanide-insensitive Rb influx was measured on whole-blood samples in 24 mM Rb_o in HBS pH 7.4 at 37°C. (A) Fluxes in mmol/kg Hb/h in SS RBCs in Cl media (♦, 4 experiments) or sulfamate media (▵, 3 experiments). Fluxes in AA RBCs in Cl media (○, 3 experiments); fluxes in AA RBCs in sulfamate (not shown) were similar to SS RBCs. (B) Rb influx normalized to VS_max KCC flux as a function of MCHC in SS and AA RBCs. For each experiment, VS_max flux was measured in cells with MCHC lower than 270 g/L (27 g/dL). Lines represent a third-order polynomial best-fit for SS (♦, solid line) and AA (○, dashed line) RBCs.