Figure 6

NOX2 activation by PMA enhances the binding capacity of naloxone. COS-7-NOX2 (stably expression of NOX2 enzyme) cells were pretreated with the indicated concentrations of PMA for 20 minutes. Then cells were used for binding experiments. After incubation with ³H-naloxone for 2 hours at 4°C, cells were mixed with 10 ml of Ultima Gold scintillation fluid and counted for radioactivity. The binding data were normalized by protein concentrations. Experiments were performed in triplicate and results are expressed as percentage of total binding observed with WT COS-7 alone. **P < 0.01 compared with corresponding WT group; ^# P < 0.05 and ^## P < 0.01 compared with and without the PMA treatment group, respectively. PMA, phorbol myristate acetate.