Figure 4. Comparison of the transient outward K⁺ current (I_to) and the steady-state K⁺ current (I_ss) between CTL and ORC mouse ventricular myocytes.

A, superimposed current records illustrating I_to were obtained by subtracting the corresponding currents recorded with (Fig. 3C) and without (Fig. 3A) the inactivating prepulse. B, mean I-V relationships for I_to in CTL and ORC mice. C, representative examples of I_ss in CTL and ORC myocytes. I_ss was measured after application of 200 μm 4-AP using the inactivation prepulse protocol. D, I-V curves for I_ss recorded from CTL and ORC mice. NS, not significant.