Figure 8.

Action potentials from cardiomyocytes treated with AngII. (A) Representative action potentials waveforms from cardiomyocytes control (solid line) or treated with AngII (1 µM) for 1 hr (dashed line). Action potentials were elicited with a short (2 ms) depolarizing current injections (200–400 pA) at a frequency of 1 Hz. (B) Phase plot of the first derivative of membrane potential (dV/dt) against membrane potential (V_m) for the action potentials shown in (A). Control, empty symbols; AngII-treated, filled symbols. (C) Bar graphs (mean ± sem) of average action potentials duration (APD) estimated at 20%, 50% and 90% repolarization, APD₂₀, APD₅₀ and APD₉₀, respectively. (D) Bar graph (mean ± sem) of maximal action potential amplitudes (Overshoot), threshold potentials and mean resting membrane potentials (RMP). (E) Bar graph (mean ± sem) of maximum rate of potentials change (dV/dt). For each bar graph, empty bars represents cardiomyocytes control and hatched bar cardiomyocytes treated with AngII (1 µM) for 1 hr. (n = 7–10) *p < 0.01 with respect to control.