摘要目的 比较鞘内注射神经肽S(neuropeptide S,NPS)和加巴喷丁对神经病理性疼痛大鼠痛行为及焦虑行为的影响,并探讨对N-甲基-D-天冬氨酸(N-methyl-D-aspartic acid,NMDA)受体的作用机制. 方法 选用鞘内置管成功的雄性Sprague-Dawley (SD)大鼠72只,采用随机数字表法随机分为6组(每组12只):假手术组(sham组)、坐骨神经慢性压榨(chronic constriction injury,GCI)动物模型组(CCI组)、神经肽S低剂量组(NPSl组)、神经肽S高剂量组(NPSh组)、加巴喷丁低剂量组(Gbl组)和加巴喷丁高剂量组(Gbh组).制备CCI动物模型,自术后7d起每日鞘内注射相应药物,在术后14 d检测机械缩足反射阈值(mechanical withdrawal threshold,MWT)和热辐射缩足反射潜伏期(foot withdrawal lantency,FWL),并通过高架十字迷宫(elevated plus-maze,EPM)和旷场试验检测焦虑行为,检测后处死动物,采用免疫荧光技术和Western blot方法检测脊髓背角N-甲基-D-天冬氨酸受体1(N-methyl-D-aspartic acid receptor 1,NR1)的表达. 结果 与假手术组比较,CCI组大鼠术后14d出现明显疼痛和焦虑行为(P＜0.01),与CCI组大鼠MWT值(2.7±1.3)g和FWL值(3.9±0.6)s比较,NPSh组、Gbl组和Gbh组大鼠14d的MWT值分别为(4.5±1.7)、(5.4±1.0)、(8.1±3.6)g以及FWL值分别为(5.8±1.5)、(6.3±1.2)、(7.6±1.6)s,结果差异有统计学意义(P＜0.05);鞘内置管19d和CCI术后14 d对大鼠在EPM实验和旷场试验中的总运动距离和跨越的总格子数没有明显影响;在EPM实验中,只有NPSh组进入开放臂的次数(6.3±1.6)和时间占比(22.4±4.3)％与CCI组比较[(2.9±1.5),(10.9±2.7)％]差异有统计学意义(P＜0.05),NPSl组,Gbl组和Gbh组差异均无统计学意义;在旷场试验中,无论高低剂量,NPS和加巴喷丁组在进入中央格子的比率和在中央格子停留的时间都明显增加,差异有统计学意义(P＜0.05);免疫荧光和Western blot结果均显示,与假手术组比较,CCI组大鼠在术后14 d NR1表达明显增加,其变化有统计学意义(P＜0.01);鞘内注射加巴喷丁和NPSh组可抑制NR1受体表达的升高;而NPSl组对NR1表达升高没有明显抑制作用. 结论 NPS和加巴喷丁可以剂量依赖性的逆转CCI大鼠的疼痛和焦虑行为,其机制可能与NMDA受体通路有关.

abstractsObjective To investigate the effects of intrathecal injection of Neuropeptide S and Gabapentin on pain behavior and anxiety behavior in rats with neuropathic pain,and to explore the possible mechanisms of of N-methyl-D-aspartic acid(NMDA) receptor 1.Methods Seventy-two male Sprague-Dawley (SD) rats,which were successfully deployed intrathecal catheter,were randomly divided into six groups (n=12),including sham group,CCI group,neuropeptide S low-dose group (NPSl group),neuropeptide S high-dose group (NPSh group),gabapentin low dose group (Gbl group) and gabapentin high dose group(Gbh group).Pain-related behaviors,depression-related behaviors,and expression of NMDA receptor1 in the dorsal horn of the spinal cord were measured at 14 d after 7 d via intrathecal injection.Results Compared with the sham group,the rats suffering CCI demonstrated significant pain and anxiety behavior (P＜0.01).High dose NPS and each dose gabapentin (but not low dose NPS) can significantly reduce mechanical withdrawal threshold (MWT) [(2.7±1.3) g vs (4.5±1.7),(5.4±1.0),(8.1±3.6) g]and thermal hyperalgesia foot withdrawal lantency(FWL) [(3.9±0.6) s vs (5.8± 1.5),(6.3± 1.2),(7.6± 1.6) s] compared with CCI group(P＜0.05).In the EPM test,compared with CCI group,only high dose NPS significantly extended numbers entries into the open arms (6.3±1.6 vs 2.9±1.5)(P＜0.05) and time spent in the open arms(22.4±4.3)％ vs (10.9±2.7)％(P＜0.05).In the open field test,each dose NPS and gabapentin added the proportion of central Zone cross (P＜0.05) and time spent (P＜0.05).Immunofluorescence and western blot experiments showed that,regardless of the level measurement group,both drugs can suppress the increase NR1 receptor expression in the dorsal horn of the spinal cord,and has a statistical significance.Conclusions Neuropeptide S and gabapentin dosedependent pain and anxiety behavior reversal CCI rats,which may be related NMDA receptor pathway.