Figure 3.

Lack of effect of CRN on voltage-dependent characteristics of L-type Ca²⁺ channel current (I_Ca-L) in rat cardiomyocytes. (A) The steady-state activation curves were calculated as normalized conductance values from the current-voltage curves before and 2 min after exposure to CRN (50 µM; n = 7). (B) Steady-state inactivation curve, I_Ca-L at the test step to 0 mV was normalized to maximum current and plotted against the potential of a 1 s inactivating conditioning prepulse between −60 and +60 mV before and 2 min after exposure to CRN (n = 5). (C) Time constant of recovery from inactivation of I_Ca-L. Depolarizing pulses were applied every 6 s at a holding potential of −40 mV. The recovery from inactivation was fitted by a single exponential (n = 5). Recovery was complete in about 1 s. CON, control; CRN, canrenone.