Figure 6. Decreased Na_v1.5 expression in Scn5a ^+/− mice.

A. Representative Western blots showing the expression levels of Na_v1.5 in WT mice and Scn5a ^+/− mice (mean age = 18±1 weeks) with a mild or a severe phenotype. Protein loading was controlled by anti-actin immunoblotting. B. Quantification of Na_v1.5 expression in WT mice (open bars) and Scn5a ^+/− mice with mild (grey bars) and severe (black bars) phenotype was performed on Western blots from 10 mice in each group by normalizing the intensities of the Na_v1.5 bands to the actin bands. ***, p<0.001 versus WT; †, p<0.05 versus mild Scn5a ^+/− mice. C. Confocal images of Na_v1.5 in ventricular cardiomyocytes isolated from WT mice (left panel) and Scn5a ^+/− mice with mild (middle panel) and severe (right panel) phenotype. Scale bar, 20 µm. In Scn5a ^+/− images presented, a WT cardiomyocyte is also included in the image frame (yellow arrows) to illustrate the clear difference in WT versus Scn5a ^+/− intercalated disc staining intensities.