Figure 6.

Effect of 5‐HMF on current density (A), steady‐state activation (B), steady‐state inactivation (C) and % recovery from inactivation (D) of I_Ca,L in GPV cardiomyocytes before (open circles) and after 1 mM 5‐HMF perfusion (5 min). I_Ca,L was elicited by a train of voltage pulses from −40 to +90 mV (10 mV interval, 400 ms) preceded by a pre‐pulse from −80 to −40 mV (50 ms). To determine steady‐state inactivation, I_CaL was activated with test pulses to +10 mV (400 ms) preceded by conditioning prepulses from −45 to +50 mV (5 mV increment, 400 ms). The amplitude of I_Ca,L during the test pulse was normalized to the highest value and plotted as a function of prepulse potential. The steady‐state inactivation curve was fitted within a V_m range from −45 to +10 mV. The % recovery from inactivation of I_Ca,L was examined using two depolarizing pulses to +10 mV with varying inter‐pulse intervals (10–5000 ms) applied from a holding potential of −40 mV every 8 s. Measurements on multiple cells derived from a single animal were averaged and counted as an individual experiment. Values are expressed as mean ± SEM of n experiments. n = 9 (A), 8 (B), 10 (C) and 7 (D). *P < 0.05, significantly different from control; paired t‐test.