Fig. 6

Abnormal caffeine-evoked Ca²⁺ release in KO-cardiomyocytes. A The left panel: The representative line-scan image of caffeine-evoked Ca²⁺ release in WT-cardiomyocytes and KO-cardiomyocytes stained with Fluo-4. The right panel: Ca²⁺ transients profile induced with 20 mM caffeine in Ca²⁺-free conditions derived from the left panel. B–D Quantification of peak, time to peak, and decay time in caffeine-evoked Ca²⁺ transients WT-cardiomyocytes and KO-cardiomyocytes, n = 6. ***P < 0.001; ****P < 0.0001; unpaired two-sided Student’s t test. E Schematic of the process of the contractility assess. F Contractility graph of WT-cardiomyocytes and KO-cardiomyocytes. G Quantification of contractility in WT-cardiomyocytes and KO-cardiomyocytes based on panel F. n = 3 independent experiments. **P < 0.01; unpaired two-sided Student’s t test