ghrelin在缺血预处理抗大鼠海马神经元缺血再灌注损伤中的作用  

Role of ghrelin in the protective effect of ischemic preconditioning against ischemia/reperfusion injury of rat hippocampal neurons

作　　者：刘亚君[1] 陈筱南[2] 陈连璧[3] 

机构地区：[1]中国医学科学院微循环研究所,北京100005 [2]山东省医学科学院附院 [3]山东杏林科技职业学院

出　　处：《上海医学》2011年第6期463-466,I0001,共5页Shanghai Medical Journal

基　　金：中国医学科学院协和青年基金;山东省自然科学基金(Y2005C69)资助项目

摘　　要：目的探讨ghrelin在脑缺血预处理(IPC)保护海马神经元缺血再灌注损伤中的作用及其与线粒体解耦联蛋白-2(UCP2)表达的关系。方法采用四血管阻断法建立全脑缺血模型,将大鼠随机分为对照组(CON组,只进行假手术)、缺血再灌注组(I/R组,大鼠在电凝椎动脉24 h后接受8 min的致死性缺血及再灌注)、IPC+I/R组(大鼠先给予3 min的短暂IPC,灌注72 h后,再给予致死性脑缺血8 min及再灌注)、I/R+ghrelin组(I/R+G组,大鼠在8 min致死性缺血后立即腹腔注射ghrelin 0.4 mg/kg,1次/d,连续注射3 d)、I/R+0.9%氯化钠溶液组(I/R+N组,以同体积0.9%氯化钠溶液替代I/R+G组中的ghrelin)、对照+0.9%氯化钠溶液组(CON+N组,在CON组的基础上每天腹腔注射与I/R+G组中ghrelin同体积的0.9%氯化钠溶液)。应用酶联免疫吸附试验检测缺血再灌注后血浆ghrelin水平。大鼠注射ghrelin后,应用苏木精-伊红(H-E)染色观察海马CA1区神经元的组织形态学变化,免疫组织化学法测定海马CA1区Bcl-2表达,反转录-聚合酶链反应检测海马UCP2 mRNA表达。结果致死性缺血再灌24 h后,IPC+I/R组血浆ghrelin水平较CON组和I/R组显著升高(P值均<0.01),并且持续72 h(P值均<0.01)。注射ghrelin后,I/R+G组存活神经元数目显著多于I/R+N组(P<0.01),但显著少于CON+N组(P<0.01)。I/R+G组海马CA1区UCP2 mRNA表达显著多于CON+N组和I/R+N组(P值均<0.01)。结论 IPC能促进ghrelin释放,并通过ghrelin上调海马CA1区神经元UCP2的表达,减轻缺血再灌注损伤。Objective To explore the role of ghrelin in the neuro-protective effect of ischemic preconditioning（IPC） against ischemia/reperfusion injury of hippocampal neurons and to discuss its relationship between ghrelin and uncoupling protein 2（UCP2）.Methods A rat 4-vessel global ischemia model was established.Rats were divided into control group（CON group,with sham operation）,ischemia/reperfusion group（I/R group,after 24 h of the electric coagulation of vertebral arteries,rats underwent an 8-min lethal ischemia followed by 72 h reperfusion）,IPC＋I/R group（the rats underwent a 3-min sublethal ischemia,72 h later underwent an 8-min lethal ischemia,and then 72 h of reperfusion）,I/R＋ghrelin group（I/R＋G group,a daily i.p.injection of ghrelin,at a dose of 0.4 mg/kg,was administered to rats immediately after the 8-min lethal ischemia for 3 days）,I/R＋saline group（I/R＋N group,rats received an i.p.injection of 0.9% sodium chloride after the 8-min lethal ischemia at the same volume and frequency as ghrelin treatment）,and CON＋N group（an i.p.injection of 0.9% sodium chloride was administered to sham operated rats at the same volume and frequency as ghrelin treatment）.The serum ghrelin levels were measured by ELISA at 24 h,48 h and 72 h after I/R.The morphological changes of neurons in hippocampal CA1 region were examined by H-E staining.Bcl-2 expression in neurons of the same region was detected by immunohistochemistry,and UCP2 mRNA expression in hippocampal neurons was assayed by reverse transcriptase-polymerase chain reaction（RT-PCR）.Results At 24 h after lethal ischemia,the serum ghrelin level in IPC＋I/R group was significantly higher than those in CON group and I/R group（P0.01）,and the high level remained until 72 h after lethal ischemia（P0.01）.After administration of ghrelin,the number of surviving neurons in I/R＋G group was significantly more than that in I/R＋N group（P0.01） and less than that in CON＋N group（P0.01）.The expression of UCP2 mRNA in I/R＋G grou

关 键 词：缺血预处理 缺血再灌注损伤 海马 神经元 GHRELIN 线粒体解耦联蛋白-2 

分 类 号：R743[医药卫生—神经病学与精神病学]