鞘内应用右美托咪定改善完全弗氏佐剂诱导的大鼠慢性炎性痛行为及其机制研究  

The improvements and mechanism of intrathecal dexmedetomidine on complete Freund's adjuvant-induced chronic inflammatory pain behavior in rats

作　　者：吴黄辉[1,2] 尹俊滨[3] 陈宇[1,2] 陈国忠[1,2] 

机构地区：[1]福建医科大学福总临床医学院,福州350108 [2]南京军区福州总医院麻醉科,福州350025 [3]第四军医大学人体解剖与组织胚胎学教研室暨梁銶琚脑研究中心,西安710032

出　　处：《神经解剖学杂志》2014年第2期159-166,共8页Chinese Journal of Neuroanatomy

基　　金：福建省重点课题(2012Y0054)

摘　　要：目的:观察鞘内应用右美托咪定(dexmedetomidine,DEX)对完全弗氏佐剂(complete Freund’s adjuvant,CFA)诱导的大鼠慢性炎性痛行为的改善作用并探讨其机制。方法:足底注射CFA制备大鼠慢性炎性痛模型,经鞘内给予不同剂量的DEX,采用辐射热法连续观察给药后大鼠痛行为,评价单次给药后的镇痛持续时间,并计算半数有效量(50%effective dose,ED50);旷场和转棒试验观察鞘内应用不同剂量DEX对大鼠运动功能的影响;应用免疫组织化学染色和Western Blot方法观察连续给予DEXED507 d后大鼠腰膨大平面脊髓背角星形胶质细胞活化程度。结果:鞘内应用DEX呈剂量依赖性地改善CFA诱导的大鼠辐射热痛敏且不影响运动功能;鞘内持续应用DEXED50可产生持久的镇痛效应;免疫组织化学染色和Western Blot结果均表明,与对照组相比,持续给药7 d后慢性炎性痛大鼠腰膨大平面脊髓背角星形胶质细胞的活化程度显著减轻(P<0.05)。结论:鞘内应用DEX可剂量依赖性改善CFA诱导的大鼠慢性炎性痛,连续给药可产生持久的镇痛效果,其机制可能与抑制脊髓星形胶质细胞活化有关。Objective： To investigate the improvements and potential mechanism of intrathecal dexmedetomidine （DEX） on complete Freund＇s adjuvant （CFA）-induced chronic inflammatory pain behavior in rats. Methods： Chronic inflammatory pain model was built by unilateral intraplantar injection of CFA in rats. Different dose strategies of DEX were admin- istrated via intrathecal route. Radiant heat method was applied to investigate the pain behavior continually, and to evalu- ate the analgesia duration after single dose of intrathecal DEX administration in rats. Then, 50% effective dose （ EDso ） was calculated. Open field （OF） and rotarod test were applied to evaluate the rats＇ motor function after intrathecal DEX administration. Immunohistochemical staining and Western Blot was applied to qualitatively and semi-quantitatively analyze the spinal astrocytic activation after a 7 d consecutive intrathecal DEXED50 administration. Results： Intrathecal DEX significantly and dose-dependently improved pain behavior in a CFA-induced chronic inflammatory rats＇ model without any obvious motor function impairments. Persistence analgesia was achieved and both immunohistochemical staining and Western Blot were revealed that compared with control group, spinal astrocytic activation was markedly inhibited （P 〈 0.05） when a consecutive intrathecal administration protocol was performed. Conclusion： Intrathecal DEX achieves a dose-dependent analgesia in a CFA-induced chronic inflammatory rats＇ model. The persistent analgesia after consecutive intrathecal administration correlates with the inhibition of spinal astrocytic activation.

关 键 词：右美托咪定 鞘内给药 完全弗氏佐剂 痛行为 机制 大鼠 

分 类 号：R614[医药卫生—麻醉学]