低声压级次声对神经病理性疼痛大鼠脊髓趋化因子介导炎症反应的影响

Effect of low sound pressure level infrasound on chemokine-mediated inflammatory response in spinal cord of neuropathic pain model in rat

目的探讨低声压级次声对神经病理性疼痛大鼠脊髓趋化因子介导炎症反应的影响。方法 72只健康雄性SD大鼠采用随机数字表分为三组,假手术组(Sham组)、神经病理性疼痛组(NP组)和低声压级次声干预组(LNP组),每组24只。制备大鼠坐骨神经慢性压迫性损伤模型。Sham组大鼠仅暴露坐骨神经而不结扎,其余操作均与NP组和LNP组相同。LNP组大鼠于造模后第4天开始接受低声压级次声治疗,每天4h,连续进行21d。所有大鼠均于术前1d(T_0)和术后3d(T_1)检测机械缩足阈值(MWT),分别于术后10d(治疗7d,T_2)、17d(治疗14d,T_3)和24d(治疗21d,T_4),每组各随机取8只大鼠检测MWT,实时荧光定量PCR技术检测脊髓组织中单核细胞趋化蛋白-1(MCP-1)、趋化因子受体2(CCR2)、TNF-α、IL-1β和IL-6基因表达,Western blot法检测脊髓组织中MCP-1和CCR2蛋白含量。结果 T_1~T_4时NP组和LNP组大鼠MWT明显低于T_0时和Sham组,且LNP组大鼠MWT明显高于NP组(P<0.05)。T_2~T_4时NP组和LNP组大鼠脊髓组织中MCP-1、CCR2、TNF-α、IL-1β和IL-6mRNA相对表达量明显高于Sham组(P<0.05);T_3、T_4时LNP组大鼠脊髓组织中MCP-1、CCR2、TNF-α、IL-1β和IL-6mRNA相对表达量明显低于NP组(P<0.05)。T_2~T_4时NP组和LNP组脊髓组织中MCP-1和CCR2蛋白含量明显高于Sham组,T_3、T_4时LNP组脊髓组织中MCP-1和CCR2蛋白含量均明显低于NP组(P<0.05)。结论低声压级次声可有效缓解神经病理性疼痛大鼠疼痛症状,机制可能与抑制趋化因子介导的级联炎症反应有关。

Objective To investigate the effect of low sound pressure level infrasound on chemokine-mediated inflammatory response in spinal cord in rats with neuropathic pain.Methods Seventy-two healthy male SD rats were randomly divided into sham operation group（group Sham）,neuropathic pain group（group NP）and low sound pressure level infrasound intervention group（group LNP）,24 in each.The sciatic nerve injury models were established.3dafter the model constructed,the rats in group LNP started to receive low sound pressure level infrasound therapy,4hper day,continued for 21 d.1dbefore surgery（T0）and 3dafter surgery（T1）,all rats were detected mechanical paw withdrawal threshold（MWT）.Respectively,after treated for 7d（T2）,14d（T3）and21d（T4）,eight rats were randomly selected from each group and their MWT was measured.The expressions of MCP-1mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,and IL-6mRNA in spinal cord in rats were detected using quantitative PCR,the expressions of MCP-1protein and CCR2 protein in spinal cord in rats were detected by using Western blot.Results MWT in groups NP and LNP at T1-T4 was lower than that of group Sham,and that in group LNP at T3-T4 were higher than that of group NP,respectively（P〈0.05）.Compared with group Sham,the relative expression levels of MCP-1mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,and IL-6mRNA in spinal cord tissues in groups NP and LNP at T2-T4 were increased（P〈0.05）;compared with group NP,the relative expression levels of MCP-1mRNA,CCR2 mRNA,TNF-αmRNA,IL-1β mRNA,and IL-6mRNA in spinal cord were decreased in group LNP at T3-T4（P〈0.05）.Western blot analysis showed that the relative expression levels of MCP-1protein and CCR2 proteinin spinal cord in groups NP and LNP at T2-T4 were higher than that of group Sham,while relative expression levels of MCP-1protein and CCR2 proteinin spinal cord in group LNP at T3-T4 were lower than that of group NP.Conclusion The low sound pressure level infrasound could effectively reduce neuropathic pain in rats,possibly via inhibiting chemokine-mediated cascade inflammatory reaction.