缺血后适应对在体大鼠心肌缺血再灌注损伤的保护作用及其机制  

Protective effect and mechanism of ischemic postconditioning in rats underwent myocardial ischemiareperfusion injury

作　　者：张苗苗 毛雯 仝其广 于海奕[2] 高炜[2] 

机构地区：[1]煤炭总医院心内科,北京100028 [2]北京大学第三医院心内科

出　　处：《中华心血管病杂志》2016年第7期616-620,共5页Chinese Journal of Cardiology

摘　　要：目的探讨缺血后适应对在体大鼠缺血再灌注损伤后心肌梗死面积和血液动力学指标的影响及其机制。方法将30只雄性SD大鼠按照随机数字表法分为假手术组、缺血再灌注组（IR组）和缺血后适应组（PC组），每组10只。通过结扎左冠状动脉前降支近段30min，再灌注2h建立大鼠缺血再灌注模型（IR组）。PC组为在再灌注开始瞬间实施再灌注30S、缺血30S，共3个循环，随后恢复再灌2h。通过颈动脉插管测定不同组大鼠的血液动力学指标；采用伊文思蓝和氯化三苯基四氮唑染色法测定缺血面积和梗死面积；分别通过Westernblot和实时定量PCR检测各组大鼠再灌注2h缺血心肌预测的靶基因Bcl-2家族促凋亡蛋白之-Bim蛋白及微小RNA（miR）-214的表达水平。结果（1）各组大鼠血液动力学的检测结果：IR组和PC组大鼠左心室收缩压（LVSP）、左心室内压最大上升速率（＋dp／dtmax）及最大下降速率（-dp／dtmax）和心率均较假手术组低，左心室舒张末压（LVEDP）较假手术组高，差异均有统计学意义（P均〈0．05）。PC组大鼠LVSP、＋dp／dtmax和-ap／dtmax，均较IR组高，LVEDP较IR组低，差异均有统计学意义（P均〈0．05）。（2）各组大鼠心肌缺血和梗死范围的检测结果：Pc组大鼠心肌缺血区面积（AAR）占左心室面积（LV）的比例（AAR／LV）与IP组比较差异无统计学意义[（27．00±7．55）％比（26．67±11．68）％，P〉0．05]，梗死面积（Is）占AAR的比例（IS／AAR）则低于IR组[（30．67±3．51）％比（48．67±4．62）％，P〈0．05]。（3）各组大鼠缺血心肌Bim蛋白表达的检测结果：IR组大鼠缺血区心肌组织中Bim蛋白表达水平高于假手术组（2．34±0．15比0．75±0．05，P〈0．05）。PC组大鼠缺血区心肌组织中Bim蛋白表达水平则低于IR组（1．25±0．14比2．34±0．15，P〈0．05）。（d）各组大鼠缺血心肌miR-214Objective This study is designed to observe the effect of ischemic postconditioning in rats underwent acute myocardial ischemia/reperfusion injury and to investigate the related mechanism. Methods A total of 30 SD rats were randomly divided into sham operation group （ control group, n = 10） , ischemia/reperfusion group （IR group, n = 10） and ischemic postconditioning group （PC group, n = 10） based on random number table. Rats in IR group underwent 30 minutes myocardial ischemia by occlusion of the proximal portion of left anterior descending （LAD） coronary artery followed by 2 hours reperfusion. In control group, there was no IR intervention. In PC group, at the start of reperfusion, three cycles of 30 seconds reperfusion and 30 seconds LAD reocclusion preceded the 2 hours of reperfusion. The hemodynamic values were measured via a cannula inserted into the right common carotid artery. The area at risk wasassessed by Evans blue staining and the infarct size as measured by TFC staining. Western blot and Real time PCR were respectively used to assess the expression of predicted target gene Bim and microRNA-214 （miR- 214） in the area at risk at the end of 2 hours reperfusion. Results （ 1 ） The hemodynamic monitoring in different groups： the left ventricular systolic pressure （LVSP）, dp/dt and heart rate of IR group and PC group were lower than those of control group, but left ventricular end-diastolic pressure （LVEDP） was higher than that of control group （all P 〈 0. 05 ）. The LVSP and ± dp/dtmx of PC group were higher than those of IR group, and LVEDP was lower than that of IR group （ all P 〈 0. 05 ）. （2） Myocardial ischemia area and infarction range in different groups： there was no statistically difference in the proportion of area at risk （AAR） in left ventricle （LV） （AAR/LV） between PC group and IP group （ （27.00 ± 7.55） % vs. （26. 67 ± 11.68） %, P 〉0. 05）. The proportion of infarct size in the area at risk（IS/AAR） of PC group

关 键 词：心肌再灌注损伤 缺血后适应 

分 类 号：R542.2[医药卫生—心血管疾病]