FIGURE 1.

Peroxynitrite generation from co-generated O₂^˙̄ and ^•NO. a, schemes showing the formation of O₂^˙̄ from incubations containing hypoxanthine (100 μm) and xanthine oxidase (0–0.4 milliunits/ml) in a phosphate buffer (pH 7.4; 50 mm) containing DTPA (100 μm), ^•NO generation from a thermal decomposition of DPTA-NONOate (0–50 μm) and ONOO⁻ formed from co-generated O₂^˙̄ from HX/XO, and ^•NO from DPTA-NONOate. b, stimulation of ONOO⁻ from RAW 264.7 macrophages using a mixture of PMA (200 ng/ml, IFN-γ (50 units/ml), and LPS (0.5 μg/ml). ^•NO is produced from induction and activation of inducible nitric oxide synthase (iNOS), and superoxide is generated from activation of NADPH oxidase by PMA.