Figure 3. Specificity of isoproterenol effects on IKur,d.
A, representative recordings under control conditions and after addition of 5 mM TEA (voltage protocol in inset). B, currents recorded before and after addition of 5 mM TEA in the presence of 0·1 μM isoproterenol from same cell as shown in panel A. C, TEA-sensitive current obtained by digital subtraction of currents in the presence of TEA from those in its absence under control conditions or in the presence of 0·1 μM isoproterenol (Iso). D, average current density-voltage relations for TEA-sensitive currents for six cells studied under both control conditions and in the presence of 0·1 μM isoproterenol. ***P < 0·001 vs. control at same voltage.