Figure 4. Effects of GSK3 inhibitors SB216763 or GSK-XIII on K⁺ independent (NCX) and K⁺ dependent (NCKX) Na⁺/Ca²⁺ exchanger activity in DCs.

A,B. Representative original tracings showing [Ca²⁺]_i in Fura-2/AM loaded gsk3^WT without (control, open circles) or with (closed circles) SB216763 treatment (1 µM, 30 min) DCs prior to and following removal of external Na⁺ (0 Na⁺) at 0 mM K⁺ (A) and at 40 mM K⁺ (B). C,D. Arithmetic means ± SEM of the peak (left) and slope (right) values of [Ca²⁺]_i increase following removal of external Na⁺ at 0 mM K⁺ (C, n = 24–51) and at 40 mM K⁺ (D, n = 43–46) in gsk3^WT DCs, without (white bars) or with (black bars) SB216763 treatment (1 µM, 30 min). *(p<0.05), unpaired t-test. E,F. Arithmetic means ± SEM of the peak (left) and slope (right) values of [Ca²⁺]_i increase following removal of external Na⁺ at 0 mM K⁺ (E, n = 47–82) and at 40 mM K⁺ (F, n = 43–46) in gsk3^WT DCs without (white bars) or with (black bars) GSK-XIII treatment (10 µM, 30 min). *(p<0.05), unpaired t-test or Mann–Whitney U test.