Figure 2. Andrographolide inhibited I_Na in a concentration dependent manner in LVMs and LAMs.

Representative whole-cell recordings of I_Na in LVMs (A) and LAMs (B) with or without 1, 5, 10, or 20 μM andrographolide. Current voltage relationships for I_Na in LVMs (C) and LAMs (D) Data are shown as means±SD (ventricle, n=10; atrium, n=8). ^#p<0.01 vs control, ^%p<0.01 vs 1 μM, ^$p<0.01 vs 5 μM, ^&p<0.01 vs 10 μM andrographolide. Representative I_Na recordings before (E) and after (F) andrographolide treatment using the inactivation protocol in the inset. Steady-state activation and inactivation curves for I_Na in LVMs (G) and LAMs (H) with or without 20 μM andrographolide. Lines represent data fit to a Boltzmann distribution function. Dose-reaction relationship between andrographolide and percent inhibition of I_Na (ventricle, n=10; atrium, n=10) (I)⁺p>0.05 vs ventricle.