氯胺酮对慢性坐骨神经损伤大鼠脊髓背角异位放电的影响  

Effect of intravenous ketamine on the ectopic discharges of the spinal dorsal horn in rats with chronic constriction injury

作　　者：袁维秀[1] 张宏[1] 李菁锦[2] 吕国蔚[2] 

机构地区：[1]解放军总医院麻醉科,北京市100853 [2]首都医科大学神经生物系

出　　处：《临床麻醉学杂志》2005年第5期341-343,共3页Journal of Clinical Anesthesiology

摘　　要：目的探讨氯胺酮静脉注射对慢性坐骨神经损伤(CCI)大鼠脊髓背角异位放电的影响。方法雄性SD大鼠36只,随机分为假手术组、CCI组和CCI-氯胺酮组。按Bennett等方法制作CCI模型,术后14d以von-Freyfilaments(vFFs)和冷水分别测定触痛和冷刺激反应,采用细胞外微电极记录技术,记录各组大鼠脊髓背角广动力(WDR)神经元的异常电活动情况。结果CCI组脊髓背角WDR细胞的基础放电水平明显高于假手术组,对轻刷、vFFs刺激放电频率与假手术组比较分别增加276·2%、245·1%和144·5%(P<0·01);氯胺酮对CCI大鼠WDR细胞基础放电和轻刷、vFFs刺激诱发放电产生剂量依赖性抑制作用。结论脊髓背角神经元的异位放电是形成中枢敏化的重要原因之一,可能与N-甲基-D-天冬氨酸(NMDA)受体有关。Objective To investigate the effect of intravenous administration of ketamine(0.05-2.0 mg/kg) on the responses of wide dynamic range (WDR) neurons of the spinal dorsal horn in rats with chronic sciatic constriction injury(CCI).Methods Thirty-six SD rats weighing 160-180 g were randomly divided into 3 groups: In groupⅠ(n=6) the animals were shamfully operated, In group Ⅱ(CCI,n=6), the rats were placed four loose ligatures around the sciatic nerve, In group Ⅲ (CCI-Ket, n=24), the spinal cord of the animals was exposed and the responses of the WDR neurones was displayed by a method for in vivo single unit extracellular recordings and ketamine (0.05, 0.5, 1.0, 2.0 mg/kg) was administered intravenously on the 14 th days after operation.Results Intravenously administered ketamine induced dose-dependent inhibition of ectopic neuronal activity in the spinal cord of CCI rats. Conclusion NMDA receptor activation contributes to the generation of ectopic discharges in WDR of the spinal dorsal horn and NMDA receptor may play an important role in the genesis of neuropathic pain.

关 键 词：氯胺酮 慢性坐骨神经损伤 大鼠 脊髓背角 异位放电 CCI 脊髓细胞 

分 类 号：R96[医药卫生—药理学]