急性痛风性关节炎大鼠关节滑膜核因子-κB水通道蛋白4P物质基因表达和丘脑腹后外侧核痛敏神经元放电频率变化规律

Expression level of nuclear factor-kappa, substance P and aquaporin 4 gene in the joint synovium and the change of discharge frequency of pain sensitive neuron in the ventral posteriolateral thalamic nucleus of acute gout rats

目的动态观察急性痛风性关节炎（AGA）大鼠关节滑膜核转录囚子（NF—κB）、水通道蛋白-4（AQP4）、P物质（SP）基因表达和丘脑腹后外侧核（VPL）痛敏神经元（PSN）放电频率变化规律，探讨AGA的神经源性炎症机制。方法48只雄性Wistar大鼠，随机分为对照组（6只）和实验组（共7组，42只）。实验组又根据注射尿酸钠（MSU）后小同时间点分为0．5、2、6、12、24、48、72h组，每组6只。于相应时间点记录各组大鼠VPL核PSN放电频率变化后，取大鼠关节滑膜组织，聚合酶链反应（PCR）柃测其NF-κB、SP和AQP4基因表达。结果AGA大鼠VPL核PSN放电频率和关节滑膜SP基因表达于注射MSU后即刻增加，6h达高峰（P〈0．05），12h后逐渐减少，AGA大鼠灭节滑膜NF—κB和AQP4基因表达于注射MSU后0．5h开始增加，12h达高峰（P〈0．05），24h后逐渐减低。经统计学相父性分析，NF—κB、SP、AQP4基因表达和PSN放电频率之间存在正柑关（r=0．8875，0．9445，0．8126，P〈0．05）。结论丘脑VPL核PSN放电频率和SP基因表达水平可作为反映AGA大鼠关节疼痛严重程度的客观指标；NF—κB和SP基因表达可作为反映其组织炎症和神经源性反应严重程度的指标；AQP4基因表达可作为反映其组织水肿严重程度的指标；疼痛和神经源性炎症在AGA发病机制中发挥着重要作用；采用神经电生理学和分子生物学相结合的方法，可以从新角度研究痛风的发病机制，为开发新药和临床治疗痛风提供新思路。

Objective To investigate the expression level of nuclear factor-kappa （NF-κB）, substance P （SP） and aquaporin 4 （AQP4） gene and the change of discharge frequency of pain sensitive neurons （PSN） in the ventral posteriolateral thalamic nucleus （VPL） of acute gout （AG） rats. The neuro-genic inflammation of AG was explored. Methods Forty-eight rats were randomly divided into two groups： the control group and the AG group. According to the time interval after injection of monosodiumurate （MSU） into the the unilateral ankle joint, the AG group was subdivided into seven groups, ie. 0.5 hours group, 2 hours group, 6 hours group, 12 hours group, 24 hours group, 48 hours gronp and 72 hours group. There were 6 rats in each group. After recording of the discharge frequency of PSN in rats VPL nucleus, the expression level of NF-κB, SP and AQP4 gene in the rats joint synovium wcre evaluated at mRNA level by PCR in above mentioned time. Results In the 0.5 hours group, the discharge frequency of PSN in the rats VPL nucleus and the expression level of SP gene in the rats joint synovium had increased immediately after the injection of MSU （P〈0.05）. In the 6 hours group, they reached the peak level （P〈0.05）, and in the 12 hours group, they began to decrease gradually （P〈0.05）. In the 0.5 hours group, the expression level of NF-KB and AQP4 gene increased after the injection of MSU （P〈0.05）. However, their peak level presented at the 12 hours （P〈O.05）, and they deer-eased after 24 hours （P〈0.05）. The statistical analysis of correlation had shown that there were positive correlation among the expression level of NF-κB, substance P, AQP4 gene and the change of discharge frequency of PSN in the rats VPL nucleus. Conclusion The discharge frequency of PSN in the rats VPI, and the expression level of SP gene in the rats joint synovium can be used to evaluate the severity of pain in the AG rats. The expression level of NF-κB and SP gene can reflect the severity of neurogenie inflammation. We can know the severity of edema of the joint synovium by detecting the expression level of AQP4 gene. Pain and neurogenic inflammation play an important role in the pathogenesis of AG. Combingelectro- physiology and biochemical technique can shade light on the pathogenesis of AG from different aspects. In the meantime, it may provide a new method for developing new drugs and new approaches for clinical treatment.