Figure 2.

Inhibition of superoxide formation and detection by mitoSOX HPLC. An XO concentration of 6.25 mU/mL was chosen for continuous and sufficient superoxide formation. The yield of the superoxide-specific mitoSOX oxidation product 2-OH-mito-E+ was quantified in the presence of increasing concentrations of the superoxide scavenging enzymes PEG-SOD or native Cu, Zn-SOD (A,B) or the XO inhibitor oxypurinol (C). The reaction solution contained 0.1 M potassium phosphate buffer at pH 7.4 and 1 mM hypoxanthine and was incubated for 30 min at 37 °C. (D) Representative chromatograms are shown for the lowest inhibitor concentration. Data are mean ± SD of 3–4 independent experiments. * p < 0.05 vs. unstimulated control.