FIGURE 8.

Effect of the V4880A mutation on the propensity for SOICR. A and B, stable, inducible HEK293 cells expressing RyR2 WT (A) and V4880A (B) were loaded with Fura-2/AM. The cells were then perfused continuously with KRH buffer containing increasing levels of extracellular Ca²⁺ (0–2 mm) to induce SOICR. Fura-2 ratios were recorded using epifluorescence single-cell Ca²⁺ imaging. Caff, caffeine. C, percentages of RyR2 WT (220 cells) and V4880A (171 cells) cells that display Ca²⁺ oscillations at various extracellular Ca²⁺ concentrations. Data shown are mean ± S.E. (n = 3; **, p < 0.01 versus WT).