Figure 4.

Effects of in vivo APC on the voltage-dependent inactivation of the cardiac L-type Ca channel. (A) Representative traces of I_Ca,L and I_Ba recorded at 0 mV from a holding potential of −80 mV using Ca²⁺ and Ba²⁺ as charge carriers, respectively, are shown. The currents were scaled and superimposed. Arrow indicates zero current level. Ba²⁺ as the charge carrier removed Ca²⁺-dependent inactivation of the L-type Ca channel. (B) The fast and slow time constants of the inactivation kinetics of I_Ba in the non-APC and APC groups are plotted against test potentials. No significant differences were observed in τ_fast and τ_slow between the non-APC and APC groups (n = 10 per group).