Role of sodium ferulate in the nociceptive sensory facilitation of neuropathic pain injury mediated by P2X(3) receptor.

Neuropathic pain usually is persistent and no effective treatment. ATP plays an important role in the initiation of pain. P2X(3) receptors are localized in the dorsal root ganglion (DRG) neurons and activated by extracellular ATP. Sodium ferulate (SF) is an active principle from Chinese herbal medicine and has anti-inflammatory activities. This study observed the effects of SF on the nociceptive facilitation of the primary sensory afferent after chronic constriction injury (CCI) mediated by P2X(3) receptor. In this study, the content of ATP in DRG neurons was measured by high-performance liquid chromatography (HPLC). P2X(3) agonist-activated currents in DRG neurons was recorded by the whole-cell patch-clamp skill. The expression of P2X(3) mRNA in DRG neurons was analyzed by in situ hybridization. The ATP content of DRG was increased after CCI. In CCI rats treated with SF, the content of ATP in DRG neurons was reduced. SF decreased the increment of P2X(3) agonist-activated currents and P2X(3) mRNA expression in DRG neurons during CCI. SF may inhibit the initiation of pain and primary afferent sensitization mediated by P2X(3) receptor during CCI.