α-肾上腺素受体在脊髓损伤大鼠血管高反应性中的作用  

Role of alpha-adrenergic receptors in vascular hyperreactivity in rats with high level spinal injury

作　　者：邹最[1] 石学银[1] 吕砚[1] 徐振东[2] 时多[3] 王璐[3] 刘刚[1] 

机构地区：[1]第二军医大学附属长征医院麻醉科,上海200003 [2]复旦大学附属华山医院麻醉科,上海200040 [3]第二军医大学生物化学与分子生物学教研室,上海200433

出　　处：《中国危重病急救医学》2006年第3期176-179,共4页Chinese Critical Care Medicine

基　　金：上海市科委基金资助项目(054119522);上海市卫生局科技发展基金资助项目(024097)

摘　　要：目的研究高位脊髓横切(SCT)慢性期大鼠腹主动脉离体血管环对α肾上腺素受体(αAR)激动剂的反应性及腹主动脉1αAR、α2AR各亚型mRNA的表达量,探讨其与腹主动脉高反应性的关系。方法取SCT 4周后大鼠的腹主动脉,利用离体血管环张力测定技术,以血管环对梯度浓度去氧肾上腺素(Phe)和可乐定的收缩力,反映血管环对α1AR、2αAR激动剂的反应性;通过实时定量聚合酶链反应(PCR)测定腹主动脉1αAAR、1αBAR、1αDAR、2αAAR、2αBAR和2αCAR的mRNA表达量改变,并与假手术组比较。结果与假手术组比较,SCT 4周组大鼠腹主动脉对可乐定反应性上升(P<0.05或P<0.01),对Phe反应性无明显改变;SCT组腹主动脉1αAAR和1αDAR的mRNA表达上调(P<0.05或P<0.01),而1αBAR mRNA表达未见明显改变(P>0.05),2αAAR、2αBAR和2αCAR的mRNA表达均上调(P<0.05或P<0.01)。结论在SCT慢性期,腹主动脉高反应性的机制可能为血管对2αAR激动剂敏感性上升,2αAR mRNA表达上调。虽然1αAR mRNA表达上调,但离体血管对Phe收缩力无明显改变,1αAR可能并不是引起SCT慢性期血管高反应性的原因。Objective To explore the vascular reactivity of abdominal aorta to agonists of α-adrener gic receptors in rat with high level transection of the spimal cord ,and to quantify the expression of α- At mRNA subtypes, in order to investigate relationship between α- AR and hyperreactivity of abdominal aorta. Methods Four weeks after transection of the spinal cord at the level of 4th thoracic vertebra, the rats were sacrificed, and abdominal aorta rings were adopted to assay sensitivity to phenylephrine and clonidine witl isolated organ perfusion system, α1A-AR, α1-B AR, α1D- AR,α2A- AR, α2B- AR,α2C- AR mRNA expression were quantified by real time polymerase chain reaction （PCR）. Results Compared with abdominal aorta, of with sham operation, reactivity of aorta of rat after transection of spinal cord to clonidine was significantly higher（P〈0.05 or P〈0.01）, but difference of vascular reactivity to phenylephrine between them was no significant （P〉0. 05）. Expressions of α1A- AR mRNA, α1A- AR mRNA, α2A- AR mRNA, α2B- AR mRNA α2C- AR mRNA Were significantly higher （P〈0.05 or P〈0.01）, while the expression of α1B- AR mRNA did not vary significantly. Conclusion Vascular hyperreactivity to agonist of α2 -AR may be the mechanism o： hyperreactivity of abdominal aorta in rat after transection of spinal cord. Although α1- AR mRNA expression is higher in aorta of rat with spinal cord injury, vascular hyperreactivity is not the result of upregulation of α1- AR sensitivity.

关 键 词：脊髓横切 自主神经反射异常 Α-肾上腺素受体 血管反应性 

分 类 号：R651.2[医药卫生—外科学]