Fig. 4.

Effect of CO on mitochondrial reactive oxygen species (ROS) production in response to LPS and ATP. A: LPS-primed BMDMs were stained with MitoSOX for 15 min before stimulation with ATP for 15 min in the absence or presence of CO, and then analyzed by flow cytometry. The x-axis shows the fluorescent signal intensity, and the y-axis represents the cell number normalized as a percentage of the maximum (%max). Data are representative of 3 experiments. B: LPS-primed macrophages were treated with Mito-TEMPO (100 μM) for 30 min before incubation with ATP for 1 h in the presence or absence of CO. IL-18 secretion in the supernatants was analyzed by ELISA. Data are representative of 3 experiments. All data represent means ± SE. **P < 0.01 by unpaired, 2-tailed Student's t-test (A and B).