Figure 3. ROS involvement in bupivacaine-induced Schwann cell apoptosis. (A) After 500 µM bupivacaine treatment, the levels of intracellular ROS, measured by DCF fluorescence with flow cytometry, were increased and maintained in Schwann cells from 2 to 4 hrs. Control was overlaid (thick line), and numerals indicate increased mean value of DCF fluorescence intensity of treated cells. Direct inhibition of intracellular ROS production by simultaneous treatment of 5 mM NAC and 0.1 mM Trolox with 500 µM bupivacaine is shown in (B). (C) No significant change of NO level, another potent signaling molecule in apoptosis, was found in the early period of bupivacaine-induced Schwann cell death. The diagrams show the results of 5 independent experiments. Values are mean ± SD. *p < 0.05 statistically different from the 500 µM bupivacaine treatment group (B) or the untreated control (C).