Cardioprotection by diazoxide (DZX) in wild-type (WT) and Slo2.x knockout mouse hearts. Langendorff-perfused hearts were subjected to control ischemia–reperfusion (IR) injury alone (open symbols) or DZX + IR (filled symbols). Symbols for genotypes are the same as in figure 3. Data for controls (IR alone, no treatment) are reproduced from figure 3 and are shown for comparative purposes. (A) Cardiac function data (rate pressure product [RPP], product of heart rate × left ventricular developed pressure) throughout perfusion. RPP is expressed as a percentage of the value immediately before ischemia. Data are means ± SEM, with 95% CIs for the 60-min reperfusion time point shown adjacent to error bars (see inset to B). Insets: representative heart cross-sections stained with 2,3,5-triphenyltetrazolium chloride (upper images) and resulting pseudocolored images calculated via threshold masks and used to quantify infarct size (lower images). (B) Infarct size for control IR and DZX + IR–treated hearts from each genotype. Within each group, individual data are shown on the left, thereby indicating the number of replicates (N). Means ± SEM are on the right, with 95% CIs shown adjacent. Inset key shows position of mean, SEM, and 95% CIs on the graphs. *Statistically significant difference between control IR and DZX + IR groups (ANOVA, with post hoc unpaired t test). dKO = double knockout.