Tetramethylpyrazine Protects against Hydrogen Peroxide-Provoked Endothelial Dysfunction in Isolated Rat Aortic Rings: Implications for Antioxidant Therapy of Vascular Diseases

Figure 2

Hydrogen peroxide (H₂O₂)-induced endothelial dysfunction is reversed by catalase and NADPH oxidase inhibitors. (a) Representative traces of acetylcholine- (ACh-) induced endothelium-dependent relaxation (EDR) in H₂O₂- (200 μM) treated rings with catalase (20000 U/mL), apocynin (10 μM), or diphenyleneiodonium (DPI, 10 nM) pretreatment. (b) Effects of catalase, apocynin, and DPI on H₂O₂-provoked disruption of ACh-induced EDR. Data represent the mean ± the standard error of the mean (SEM) of 4–6 independent experiments ( versus control; versus H₂O₂).

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