Fig. 3.

Use-dependent block of rNav1.4 wild-type Na⁺ currents by 100 μM ranolazine during repetitive pulses. A, repetitive pulses at + 50 mV for 10 ms were applied at 5 Hz for a total of 60 pulses. Representative traces of Na⁺ currents were recorded in the presence of 100 μM ranolazine; the number near the trace indicates the corresponding pulse number applied. B, peak currents were measured, normalized with respect to the peak amplitude at 1P, and plotted against the corresponding pulse. The curve (solid line) was best fitted by an exponential function with a time constant of τ = 3.43 ± 0.30 pulse (n = 6).