Flow cytometry of neonatal cardiomyocytes stimulated with Ang (1µM) and loaded with MitoSOX (A) or CM-DCFDA (B). (C) Quantitative analysis (presented as mean±SEM of histogram medians, n=3–5) revealed a significant increase in MitoSOX and DCFDA fluorescence in Ang-treated cardiomyotyes (red), compared with saline treatment (black). The non-targeted antioxidant NAC (0.5mM, blue line) had no significant effect on Ang induced mitochondrial ROS (A, C) and total cellular ROS (B, C). Simultaneous treatment with SS-31 (1nM, green line) substantially reduced Ang induced mitochondrial ROS (A, C) and total cellular ROS (B, C).*p<0.01 vs. saline; #p<0.01 vs. Ang.