Fig. 3

Transient outward currents (I_to) in P19CL6-derived cardiomyocytes and P19CL6-Csx-derived cardiomyocytes. a Representative current traces from P19CL6-derived cardiomyocytes in the early stage without 4-AP (i), with 5 mmol L⁻¹ 4-AP (ii), and (iii) the difference between the two (i)–(ii). Currents were elicited by depolarizing pulses from a holding potential of ‒ 80 mV to the test potentials between ‒ 30 and + 50 mV (20 mV increments). b Current densities were plotted against test potentials in P19CL6-derived cardiomyocytes (left panel) and P19CL6-Csx-derived cardiomyocytes (right panel). *p < 0.05 compared with P19CL6 cells in the early stage