Fig. 4.

H₂O₂and antimycin A-induced oxidative stress in cardiomyocytes. Cardiomyocytes were loaded with fluorogenic dyes sensitive to ROS production. H₂DCF-DA dye (A, B) probes oxidative stress within the cytosol. Dihydrorhodamine 123 (DHR₁₂₃) dye (C, D) probes oxidative stress within the mitochondria. Fluorescence was measured every 5 min and was normalized by baseline fluorescence (T0) (A, C). In control cells (basal), the fluorescence increases modestly during the 25 min-period. Some myocytes were incubated for 1 h with either 6 μM of sinapine (SP⁶), 60 μM of sinapine (SP⁶⁰) or 60 μM of sinapic acid (SAc⁶⁰) prior to measurement. Some cells were stimulated with 0.1 mM H₂O₂ or with a mitochondrial electron transport chain complex III blocker, antimycin A (AA, 10 μM) to force mitochondria to produce ROS. The fluorescence in each condition was compared with control cells (basal). (B, D) Representative average fluorescence after 25 min from graphs A and C. (n = 4 animals) (A, B) Linear mixed model effect: Time: p < 0.001, Group: p = 0.0139, Time-Group: p < 0.001. (C, D) Linear mixed model effect: Time: p < 0.001, Group: p < 0.001, Time-Group: p < 0.001. *, p < 0.05, **, p < 0.01.