Figure 8
V0.5 vs. amplitude and slope vs. amplitude plots of INa measured from neonatal mouse ventricular cardiomyocytes using manual patch clamp. (A) Top, distribution of Ipeak amplitudes of the data set. Blue data points correspond to a subset of cells with absolute amplitudes greater than 7000 pA. Left, symbols represent V0.5 values as a function of current amplitude values. The black line corresponds to exponential fit of the data, and the orange line corresponds to fit of computed values obtained from the kinetic model that has been optimized for heterologously-expressed Nav1.5 currents in COS-7 cells and in which RS has been set to 2 M\(\Omega\). Right, mean ± sem activation V0.5 for cells with current amplitudes smaller or greater than 7000 pA. ****, p < 0.0001, **, p < 0.01, Mann–Whitney test (Ipeak) and student’s t-test (V0.5). (B) Same as in A for the slope of the activation curve. ****, p < 0.0001, **, p < 0.01, Mann–Whitney test (Ipeak) and student’s t-test (k).
