Figure 3. Possible sources of ROS: Activity of NAD(P)H oxidase (A) is induced by TNF-α in both sedentary and exercise trained animals.

In contrast, activity of xanthine oxidase (B) and mitochondrial derived ROS, indirectly measured as the ratio of aconitase to fumarase activity (C), were only altered in sedentary mice treated with TNF-α whereas exercise training prevented an increase in xanthine oxidase activity or an inhibition of aconitase/fumarase activity via mitochondrial ROS by TNF-α. *p<0.05 vs. sedentary+NaCl, §p<0.05 vs. exercise+NaCl, $p<0.05 vs. sedentary+NaCl and exercise+TNF-α, n = 10 per group.