Figure 6.

Extracellular Ca²⁺modulates the inhibitory effect of Cx30 on ENaC.A and B, representative whole-cell current traces recorded in oocytes expressing ENaC only (A) or coexpressing ENaC with Cx30 (B) incubated for 48 h in solution containing the indicated concentration of Ca²⁺ ([Ca²⁺]_o = 0.9, 1.8 or 3.6 mM). Application of amiloride (Ami, 2 μM) is indicated by filled bars. Dashed lines indicate zero current level. C, ΔI_Ami values from similar experiments as shown in the representative traces (A and B). Mean ± SEM and data points for individual oocytes are shown; ∗∗∗p < 0.001; ∗∗p < 0.01; n.s., not significant; Kruskall–Wallis with Dunn’s post hoc test (n = 24, N = 2). D, relative inhibitory effect of Cx30 on ENaC calculated from the data shown in (C) essentially as described in Figure 3. Mean ± SEM and data points for individual oocytes are shown; ∗∗∗p < 0.001; ∗∗p < 0.01; Kruskall–Wallis with Dunn’s post hoc test.