Averaged results of whole-cell current measurements in HbS cells. (A,C) Oxygenated HbS cells. (B,D) Deoxygenated HbS cells. All measurements were made using either Na⁺-containing bath solution and Na⁺-free pipette solution (NMDG⁺ substituted for Na⁺; A-B) or Ca²⁺-containing bath and pipette solution (C-D). For panels C and D, data are presented before (□) and at least 3 minutes after (▪) Gd³⁺ (50 μM) addition. Data are presented as means ± SEM, n = 10 (A), n = 8 (B), and n = 3 (C-D).