FIGURE 9.

Influence of depolarization-induced Ca²⁺ release and Ca²⁺ sparks on mitochondrial Ca²⁺ level in GFP-RyR2 ventricular myocytes. A, mitochondria in live GFP-RyR2 ventricular myocytes (n = 16) were loaded with Rhod-2 AM and visualized with confocal fluorescence imaging. B, GFP-RyR2 cluster fluorescence signals of the same cell as in A. C, merged image of the Rhod-2 labeling and GFP-RyR2 signals. D, fluorescence signals of Rhod-2 loaded GFP-RyR2 ventricular myocytes (n = 28) during and after termination of pacing at 3 Hz in the presence of 3 mm extracellular Ca²⁺. E, GFP-RyR2 cluster fluorescence signals of the same cell as in D. F, merged image of the Rhod-2 and GFP-RyR2 signals. G, cytosolic Ca²⁺ transients and Ca²⁺ sparks revealed by Fluo-4 in GFP-RyR2 ventricular myocytes (n = 16) during and after termination of pacing at 3 Hz in the presence of 3 mm extracellular Ca²⁺.