基于Cx43/mito-KATP信号轴观察右美托咪定预处理对大鼠离体缺血再灌注心脏的保护机制  

The protective mechanism of dexmedetomidine preconditioning on ischemia-reperfusion of the isolated rat heart uses the connexin43/mito-KATP signaling axis

作　　者：吴亚辉 乔梁 林洪启 WU Yahui;QIAO Liang;LIN Hongqi(Henan Provincial People’s Hospital Department of Anesthesiology,Zhengzhou 450003,China;Henan Provincial People’s Hospital Department of Otorhinolaryngology,Zhengzhou 450003;Department of Anesthesiology of Central China Fuwai Hospital,Zhengzhou 450003)

机构地区：[1]河南省人民医院麻醉科室,郑州450003 [2]河南省人民医院耳鼻喉科,郑州450003 [3]华中阜外医院麻醉科室,郑州450003

出　　处：《中国比较医学杂志》2021年第10期76-84,共9页Chinese Journal of Comparative Medicine

摘　　要：目的探讨右美托咪定预处理对大鼠离体缺血再灌注(myocardial ischemia-reperfusion injury,MIRI)心脏的保护作用以及对缝隙连接蛋白43(connexin43,Cx43)/线粒体ATP敏感性钾通道(mitochondrial ATPsensitive potassium channel,mito-KATP)信号轴的调控机制。方法构建离体心脏Langendorff灌注模型。采用随机数字表法将50个离体心脏分为5组(n=10):空白组(Blank组)、缺血再灌注组(I/R组)、缺血再灌注+右美托咪定预处理组(I/R+Dex组)、缺血再灌注+右美托咪定预处理+mito-KATP通道阻断剂5-HD组(I/R+Dex+5-HD组)、缺血再灌注+mito-KATP通道阻断剂组(I/R+5-HD组)。采用停灌30 min,再灌注120 min的方法制备大鼠离体心脏心肌缺血再灌注损伤模型。Blank组以K-H溶液持续灌流180 min;模型组以K-H溶液灌流30 min,停止30 min,再以K-H溶液灌流120 min,造成MIRI损伤;I/R+Dex组以含10 mg/L的右美托咪定的K-H溶液灌流30 min,停止30min,再以K-H溶液灌流120 min;I/R+Dex+5-HD组先以含10 mg/L的mito-KATP通道阻断剂5-羟葵酸(5-HD)的K-H溶液灌流15 min,含10 mg/L的右美托咪定的K-H溶液灌流15 min,停止30 min,再以K-H溶液灌流120 min;I/R+5-HD组先以含10 mg/L的5-HD的K-H溶液灌流30 min,停止30 min,再以K-H溶液灌流120 min。TTC染色检测各组心脏心梗死面积比例。免疫组化检测各组心脏中Cx43的表达。Western blot检测各组心脏中p-Cx43的表达水平。结果与Blank组相比,I/R组、I/R+Dex组、I/R+Dex+5-HD组、I/R+5-HD组心脏的心肌梗死面积明显升高,Cx43、p-Cx43的表达明显降低;与I/R组相比,I/R+Dex组、I/R+Dex+5-HD组心脏的心肌梗死面积明显降低,Cx43、p-Cx43的表达升高,I/R+5-HD组心脏的心肌梗死面积明显升高,Cx43、p-Cx43的表达明显降低;与I/R+Dex组相比,I/R+Dex+5-HD组、I/R+5-HD组心脏的心肌梗死面积明显升高,Cx43、p-Cx43的表达明显降低,差异均具有统计学意义(P<0.05)。结论右美托咪定预处理能够促进Cx43的表达及磷酸化,促�Objective To investigate the protective effect of dexmedetomidine preconditioning on ischemiareperfusion injury(MIRI)in isolated rat hearts and its potential regulatory mechanism via the connexin 43(Cx43)/mitochondrial ATP-sensitive potassium channel(mito-KATP)signaling axis.Methods The isolated heart Langendorff perfusion model was used.The random number table method was used to divide 50 isolated hearts into 5 groups(n=10/group):control(Blank group),ischemia-reperfusion(I/R group),ischemia-reperfusion+dexmedetomidine preconditioning(I/R+Dex group),ischemia-reperfusion+dexmedetomidine preconditioning+mito-KATP channel blocker 5-HD(I/R+Dex+5-HD group),and ischemia-reperfusion+mito-KATP channel blocker(I/R+5-HD group)groups.The rat model of isolated myocardial ischemia-reperfusion injury was prepared by stopping perfusion for 30 min and reperfusion for120 min.The Blank group was continuously perfused with K-Hsolution for 180 min.The I/R group was perfused with KH solution for 30 min,stopped for 30 min,and then perfused with KH solution for 120 min,causing MIRI injury.The I/R+Dex group was perfused with KH solution containing 10 mg/L dexmedetomidine for 30 min,stopped for 30 min,and then perfused with KH solution for 120 min.The I/R+Dex+5-HD group was perfused with KH solution containing 10 mg/L of mito-KATP channel blocker 5-hydroxykulanic acid(5-HD)for 15 min,perfused with KH solution containing 10 mg/L of dexmedetomidine for 15 min,stopped for 30 min,and then perfused with KH solution for 120 min.The I/R+5-HD group was perfused with KH solution containing 10 mg/L of 5-HD for 30 min,stopped for 30 min,and then perfused with KH solution for 120 min.Triphenyltetrazolium chloride staining was used to detect the proportion of cardiac infarction in each group.The expression of Cx43 in rat hearts from each group was detected by immunohistochemistry.Western blot was used to detect the heart expression levels of p-Cx43 in each group.Results Compared with the Blank group,the myocardial infarction area of the I/R,I/R+Dex,I

关 键 词：缝隙连接蛋白43 线粒体ATP敏感性钾通道 右美托咪定预处理 离体心脏 缺血再灌注损伤 

分 类 号：R-33[医药卫生]