Figure 2.

Effects of AGAP and W38G on voltage dependence of activation and inactivation of hNa_v1.4 and hNa_v1.5 and effects of AGAP and W38G on recovery from inactivation of Na⁺ current. Na⁺ current was generated by applying pulses from −80 to +40 mV at 10-mV steps for 20 ms from the holding potential of −80 mV in increments of 10 mV. Peak currents were converted into conductance, and normalized conductance of hNa_v1.4 (A) and hNa_v1.5 (D) was plotted against the voltages of conditioning pulses. Each point represents mean ± S.E. (n = 6). The currents were elicited with a test pulse at −20 mV for 20 ms following 30-ms prepulses ranging from −100 to 0 mV at 5-mV steps. Peak currents were normalized, and the inactivation curves of hNa_v1.4 (B) and hNa_v1.5 (E) were plotted against the command potentials. Each point represents mean ± S.E. (error bars) (n = 6). The currents were obtained at two pulses, consisting of a 200-ms prepulse to −20 mV followed by resting at −80 mV for a time varying from 2 to 56 ms in increments of 3 ms and a test pulse to −20 mV for 10 ms. The I/I_max ratio represented the recovery of Na⁺ current from inactivation for hNa_v1.4 (C) and hNa_v1.5 (F). Each point represents mean ± S.E. (n = 6).