Fig. 4.

Effect of calyculin A and WNK463 on KCC activity in red cells from patients with SCA. Red cells (20% Hct) were pre-incubated in N-MBS sequentially for two periods of 30 min in the presence of vehicle (DMSO) or drug (WNK463 40 nM or calyculin A 100 nM), as indicated. They were then equilibrated in Eschweiler tonometers for 20 min at 150 mmHg in the continued presence of WNK463 and/or calyculin A and KCC activity measured as described in the legend to Fig. 1. Histograms represent means ± SEM, n = 6. ** p < 0.01 compared to red cells incubated in the absence of WNK463; ^# p < 0.05, ^## p < 0.01 between groups as indicated.