Figure 4. CaMKII inhibition in atrial and ventricular myocytes.
A, KN-92 (1 μm) had no effect on ICaL in atrial myocytes. B, KN-93 (1 μm) reduced peak ICaL amplitude. In the presence of KN-93, BAPTA-AM (5 μm) produced a further reduction in ICaL in atrial myocytes. C, comparison of the effects of KN-92, KN-93 and BAPTA-AM on peak ICaL amplitude in atrial myocytes. D, KN-92 (1 μm) produced a small but significant reduction in ICaL in ventricular myocytes. E, KN-93 (1 μm) reduced peak ICaL amplitude. In the presence of KN-93, BAPTA-AM (5 μm) had no further effect on ICaL in ventricular myocytes. F, comparison of the effects of KN-92, KN-93 and BAPTA-AM on peak ICaL amplitude in ventricular myocytes.