Figure 2. IP₃R2 is responsible for triggering longitudinal Ca²⁺ waves under shear stress .

A and B, confocal Ca²⁺ images recorded in the representative WT (with and without 2‐APB) (A) and IP₃R2 KO mouse atrial myocytes (B) during the application of shear stress (∼16 dyn cm⁻²). Longitudinal Ca²⁺ waves were not observed during shear application when IP₃R2 was deficient. C, Ca²⁺ fluorescence measured from the ROIs with corresponding colours (inset) from the series of confocal images recorded in the cells illustrated in A and B. The time marked by arrowheads matches with 0 s shown in the confocal images. D, summary of the number of longitudinal Ca²⁺ waves and whole‐cell Ca²⁺ increases during 8‐s application of shear stress in WT cells (n = 15) with and without 2‐APB, and in IP₃R2 KO cells (n = 12). ****P < 0.0001 vs. WT (unpaired t test).