Figure 3.

Neuronal nitric oxide synthase (nNOS) mRNA levels in dorsal root ganglion (DRG) neurons under tumor necrosis factor-α (TNF-α) treatment with or without kinase inhibitors. DRG neurons were respectively pretreated with selective inhibitor for phosphatidylinositol-3 kinase (LY294002; 50 µM), protein kinase C (Go6983; 250 nM), MAPK (PD098059; 25 µM) and p38 MAPK (PD169316; 25 µM), or selective TNF-α receptor 1 inhibitor SPD304 (50 µM) for 30 min, and then incubated with TNF-α (40 ng/ml) and the kinase inhibitor or SPD304 for 25 h. DRG neurons treated with TNF-α only were used as a control. The mRNA levels of nNOS were measured and expressed as fold-changes to those of untreated cells (designated as 1). ^*p<0.05 vs. control.