活性氧对背根神经节P2X3受体介导的痛信号功能的影响

Effect of reactive oxygen species on dorsal root ganglion P2X3 receptor-induced pain signal

目的探讨活性氧(reactive oxygen species,ROS)对P2X3受体介导的神经病理性疼痛作用的影响。方法用成年雌性SD大鼠建立背根神经节慢性压迫(CCD)神经病理性疼痛模型,建模成功后随机分为4组(每组10只),经腹腔分别注射生理盐水(NS)、PBN 100mg/kg、PBN 30mg/kg、PBN 10mg/kg,给药30min后,经足底注射P2X3受体特异性激动剂α,β-meATP 50nmol,体积为50μL,持续观察注射后15min内的自发缩足次数和主动悬足时间,并整合计算每2min内的综合悬足时间(PLTPM)。结果 PBN能够剂量依赖性抑制由α,β-meATP引发的自发性痛行为,与NS组比较,PBN100mg/kg组在前6min内能明显抑制自发性疼痛,差异具有统计学意义(P<0.05),而PBN 30mg/kg组大鼠仅在2至4min时间单位表现出差异有统计学意义(P<0.05)。结论氧自由基清除剂可以有效缓解由CCD模型引发的神经病理性疼痛及P2X3受体激动剂诱发的自发痛,ROS可能作为信号分子参与了P2X3受体介导的痛觉信息的传递。

Objective To investigate the effect of reactive oxygen species（ROS） on P2X3 receptor-mediated neuropathic pain. Methods Neuropathic pain model was induced in female Sprague Dawley rats by chronic compression of dorsal root ganglia （CCD）, and the CCD rats were randomly divided into 4 groups （each group containing 10 rats）： Saline group （NS group） ; PBN 100 mg/kg treatment group; PBN 30 mg/kg treatment group; and PBN 10 mg/kg treatment group. The specific agonist of P2X3 receptor, α, β-meATP （50 nmol in 50 μL）, was subcutaneously injected into the plantar surface of the right hind paws of each rat 30 min after PBN or NS injection. The spontaneous paw flinching times and withdrawing time were observed for 15 min after injection and the paw lift time per minute （PLTPM） in every 2 minutes was calculated. Results Pretreatment with PBN inhibited α, β-meATP-induced spontaneous pain in a dose-dependent manner. Compared with the NS group, PBN 100 mg/kg group significantly inhibited flinching response during the first 6 min （P〈0.05）, while the rats in PBN 30 mg/kg group only had significantly attenuated flinching response during the second to the fourth minute compared with NS group（P〈0.05）. Conclusion Oxygen free radical scavenger can effectively alleviate the neuropathic pain caused by CCD and P2X3 receptor agonist-induced spontaneous pain. ROS may act as a messenger in P2X3 receptor-mediated pain signaling transmission.