Figure 5. Pre-treatment with clinical NO donor SNP and sGC inhibitor elicits similar protection against isoproterenol induced Ca²⁺ sparks.

Ca²⁺ transients (A) and sparks (B) from WT and CaMKIIδ-C273S cardiomyocyte were recorded at the end of a 7-minute incubation with SNP (200 μM) followed by wash-in of 100 nM ISO. Mean Ca²⁺ transient amplitude and spark frequency data are shown in C and D respectively (WT: n=10 cells, N=3 hearts; CaMKIIδ-C273S: n=23 cells, N=6 hearts). The same experiments were performed following a pre-treatment with sGC inhibitor ODQ (10 μM; 20 min incubation) with representative line-scans (E-F) and mean data (G-H) plotted for WT (n=13 cells, N=3 hearts) and CaMKIIδ-C273S (n=14 cells, N=4 hearts) cardiomyocytes.