Figure 2. Ranolazine blocks the mechanosensitive response and peak currents of endogenous Na+ channels in HL-1 cells. (A) Single Na+ current traces recorded by whole cell voltage-clamp from HL-1 cells, elicited by stepping to -30 mV from -120 mV before (black traces, Flow OFF) or during (gray traces, Flow ON) bath flow, produced by rinsing solution through the recording chamber at 10 mL/min in the absence (Control, 0 µmol/L) or presence (Ranolazine, 50 µM) of drug. (B) Mean parameters of HL-1 Na+ current in response to solution flow with or without ranolazine. From top left to bottom right, peak current density, time constant (τ) of activation, V1/2 of steady-state activation, slow time constant of inactivation (τ1), fast time constant of inactivation (τ2), and V1/2 of steady-state inactivation. (n = 5; *p < 0.05 compared with 0 mL/min flow, †p < 0.05 compared with 0 µM ranolazine, and p > 0.05 interaction between bath flow and ranolazine blockade by two-way ANOVA with Bonferroni multiple comparisons posttest).