Hydralazine inhibited mitochondrial fragmentation and reduced cell death following SIRI. (A) Representative confocal images of adult murine ventricular cardiomyocytes subjected to SIRI showed that treatment with hydralazine inhibits IRI-induced mitochondrial fragmentation when compared to vehicle control. Scale bars are 10 µm. (B) Treatment of adult murine ventricular cardiomyocytes subjected to SIRI with hydralazine reduced the mean percentage of cells with fragmented mitochondria, when compared to vehicle control. Statistical analysis was performed using the Student’s t-test. Data are expressed as mean±SEM. *P=0.034. N=4–5 independent experiments. (C) Treatment of adult murine ventricular cardiomyocytes subjected to SIRI with hydralazine reduced cell death (as evidenced by propidium iodide positive cells), when compared to vehicle control. Statistical analysis was performed using one-way ANOVA with Tukey’s multiple comparison post-test. Data are expressed as mean±SEM. ^*P<0.05. ***P<0.001. N=5 independent experiments.