Fig. 3.

Induction of ROS formation from NADPH oxidase by arsenic. Chemiluminescence measured with luminol plus HRP (A), lucigenin (B), and flow cytometry (C) by using dihydrorhodamine 123 showed significant ROS induction in NB4 cells treated with arsenic. (D and E) Luminol plus HRP (D) and cytochrome c reduction (E) showed that induction of ROS was further dramatically enhanced by the addition of 50 nM PMA. Incubation with DPI completely blunted the baseline, arsenic-induced, or PMA-stimulated chemiluminescence and cytochrome c reduction. SOD, superoxide dismutase.