Fig. 4.

Oxidative stress from TNFα-activated leukocytes is caused by mitochondrial superoxide and MPO-derived ROS from neutrophils and monocytes. TNFα-activated leukocytes from healthy donors (n = 6) were incubated with indicated various antioxidants (NAC; a pan antioxidant, Mito-Tempo; an antioxidant for mitochondrial superoxide, L-NMMA; an antioxidant for NOS, 4-ABAH; an antioxidant for MPO, apocynin; an antioxidant for NOX) for 3 h. (A-C) Total ROS, NO and mitochondrial superoxide were measured as described in methods. Results are plotted as the mean fluorescent intensity of each sample on the vertical axis with mean ± SEM. *p < 0.001 vs. control. **p < 0.001 vs. TNFα. ANOVA and Bonferroni post-hoc test.