A) SR Ca2+ loading protocol and measurement of Ca2+ load (10 mM Caffeine) after a 200 sec rest subsequent to pacing with or without TTC. B) Representative recordings of caffeine-induced SR Ca2+ release in the 4 experimental groups in the absence (upper panels) or presence (lower panels) of TTC. C) Average SR Ca2+ release with or without TTC in myocytes from Normal, ACi, ACi+nCFP, and ACi+MCU groups. In each subgroup, n=7 from 3 hearts. Data of 8 groups were analyzed with nested 2-way ANOVA followed with Tukey test for multiple comparisons. D) Representative image of fluorescently-labelled disulfide bonds of RyR2 (above) and Ponceau S staining (below). E) Average levels of fluorescently-labelled disulfide bonds of RyR2 from Normal, ACi, and ACi+MCU (n=3) groups. Data were analyzed with 1-way ANOVA followed with post-hoc Tukey test.