鞘内注射可乐定对切口痛大鼠脊髓背角PKA催化亚单位表达的影响  

Effect of intrathecal Clonidine on Expression of Protein Kinase A Catalytic Subunit in the Spinal Dorsal Horn in a Rat Model of Incisional Pain

作　　者：孔明 胡兴国[2] 

机构地区：[1]徐州第一人民医院麻醉科,21002 [2]湖南省桃源县人民医院麻醉危重医学科,415700

出　　处：《黑龙江医药》2011年第6期907-911,共5页Heilongjiang Medicine journal

基　　金：江苏省级高校重点实验室开放课题资助项目(KJS06002)

摘　　要：目的:观察鞘内注射(intrathecal injection IT)可乐定对切口痛大鼠脊髓背角PKA催化亚单位表达的影响。方法:选择鞘内置管成功的雄性SD大鼠80只,随机分为5组,每组16只,分别为假手术组,对照组,可乐定5μg组,可乐定10μg组和可乐定20μg组。按Yaksh法鞘内置管,按Brennan法制作大鼠足底切口疼痛模型,用机械缩爪反射阈值(mechanical withdrawal threshold MWT)和热缩爪潜伏期(thermal withdrawal latency TWL)来确定疼痛行为学变化,应用免疫组织化学法和免疫印迹法测定大鼠脊髓背角PKA催化亚单位表达的变化。结果:与假手术组比较,术后3h时对照组大鼠的MWT明显降低,TWL明显缩短(P<0.01),脊髓背角PKA催化亚单位免疫反应阳性神经元数量和神经元胞浆内PKA催化亚单位表达明显增加(P<0.01);与对照组比较,术前IT可乐定10μg组和IT可乐定20μg组大鼠的MWT明显增加,TWL明显延长(P<0.01),脊髓背角PKA催化亚单位免疫反应阳性神经元数量和神经元胞浆内PKA催化亚单位表达明显减少(P<0.01),尤以可乐定20μg组为甚;而IT可乐定5μg组大鼠的MWT,TWL,脊髓背角PKA催化亚单位免疫反应阳性神经元数量和神经元胞浆内PKA催化亚单位表达与对照组比较均无统计学意义。结论:在大鼠切口痛模型中,IT可乐定具有剂量依赖性抗伤害作用,其机制可能与其抑制切口痛引起的脊髓背角PKA催化亚单位的表达增加有关。Objective：To observe the effect of intrathecal clonidine on expression of protein kinase A （PKA） catalytic subunit in the spinal dorsal horn in a rat model of incisional pain. Methods：80 male Spragne -Dawley rats were divided randomly into five groups： sham group, control group, pre - incisional clonidine 5ug group, pre - incisional clonidine 10μg group and pre - ineisional clonidine 20ug group. Intrathecal catheter and the model of incisional pain were produced according to Yaksh and Brennan＇s described respectively. Changes of pain behavior were assessed by mechanical withdrawal threshold （MWT） and thermal withdrawal latency（TWL）. The expressions of PKA catalytic subunit in the spinal dorsal horn were assessed by immunohistechemical method and western blot analysis. Results： Compared with sham group, MWT and TWL in control group were decreased significantly at 3h after incision （ P 〈 0. 01 ）and the number of positive ceils and protein expres- sion of PKA catalytic subunit in the spinal dorsal horn were increased significantly in control group （ P 〈 0. 01 ）. Compared with control group,MWT and TWL in pre - incision clonidine 10ug group and pre -incision elonidine 20p, g group were in- creased significantly at 3h after incision（ P 〈0. 01 ） and pre - incision clonidine 20p,g group were most increased than any oth- er groups（ P 〈 0. 01 ）. Dose - effect analysis demonstrated that the anfinociceptive effect of intrathecal clonidlne was positively dose - related. The number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn were decreased significantly in pre - incision clonidine 10ug group and pre - incision clonidine 20pg group and pre - incision eloni- dine 20μg group were most decreased than any other groups（ P 〈0. 01 ）. However,MWT , TWL,the number of positive cells and protein expression of PKA catalytic subunit in the spinal dorsal horn changed with no statistical significance in pre - incisional donidinc 5ug group co

关 键 词：疼痛 可乐定 蛋白激酶A 脊髓 

分 类 号：R614[医药卫生—麻醉学]