低氧预适应与远隔缺血预适应第二保护窗口期在急性心肌缺血中的心肌保护作用对比

发布时间：2018-11-13 18:05

【摘要】：目的:本实验旨在通过建立SD大鼠急性心肌缺血模型,来对比低氧预适应与远隔缺血预处理两种方式在急性心肌缺血情况下的心肌保护作用。方法:选取60只SD雄性大鼠,体重284g±56g(220g~350g),随机分为4组,分别为1.空白对照组2.模型组3.低氧预适应组(HP组)4.远隔缺血预处理组(RIP组)。每组都给予普通饲料喂养。其中第3组先予以15d低氧预适应处理,第4组建模前24h予以普通橡胶带结扎大鼠尾部,形成远隔肢端缺血预处理。第2组、3组、4组大鼠予以尾静脉注射2u/kg垂体后叶素,并分别于注射后30min内观测心电监护仪II导联心电图。实验建模成功后24h胸腔采血测定心肌肌钙蛋白T(Cardiac troponin T,cTnT)、肌型肌酸激酶同工酶(Creatine kinase-MB,CK-MB)、超氧化物歧化酶(Superoxidide Dismutase,SOD)和丙二醛(Malondialdehyde,MDA)、促红细胞生成素(Erythropoietin,EPO)。取心尖部肌肉组织,甲醛固定后,石蜡包埋,制作切片,HE染色后观察其病理学改变。结果:(1)低氧预适应与远隔缺血预处理都具有良好的心肌保护作用;与模型组相比HP组与RIP组大鼠,心衰症状显著减轻,注射垂体后叶素后心电图显示J点抬高不明显,CK-MB、cTnT、MDA降低,SOD上升。HP与RIP组EPO均低于模型组,心律失常评分也低于模型组。心肌病理切片超微结果显示:较对照组心梗面积减少,心肌细胞水肿变性减轻,结构更清晰。(2)HP组与RIP组相比心律失常评分无显著差异(P0.05),CK-MB、cTnT、SOD、MDA较RIP组水平高,EPO显著高于RIP组。心衰症状统计无明显统计学差异。病理结构显示心肌细胞损伤较RIP稍严重,梗死范围较大,心肌组织中可见新生毛细血管生成。结论:(1)低氧预处理与远隔缺血预适应都能为急性心肌缺血提供显著的心肌保护作用(2)低氧预适应在降低心肌损伤标志物的水平上与心肌组织超微结构保护上弱于远隔缺血预适应的第二保护窗口期。(3)RIP组与HP组均与空白对照组在CK-MB、cTnT上有显著差异(P0.01)。
[Abstract]:Aim: to compare the protective effects of hypoxic preconditioning and distant ischemic preconditioning on acute myocardial ischemia in SD rats. Methods: 60 male SD rats, weighing 284g 卤56g (220g~350g), were randomly divided into 4 groups, 1. Blank control group 2. Model group 3. Hypoxia preconditioning group (HP group) 4. Distant ischemic preconditioning group (RIP group). Each group was fed with general feed. The third group was treated with hypoxic preconditioning for 15 days, the fourth group was treated with common rubber band ligation of the rat tail 24 hours before modeling, and the distal limb ischemic preconditioning was formed. Group 2, group 3 and group 4 were injected with 2u/kg pituitrin via caudal vein, and electrocardiogram (ECG) of II lead of ECG monitor were observed in 30min after injection. Cardiac troponin (T (Cardiac troponin), creatine kinase isoenzyme (Creatine kinase-MB,CK-MB), superoxide dismutase (Superoxidide Dismutase,SOD) and malondialdehyde (Malondialdehyde,MDA) were measured 24 hours after modeling. Erythropoietin (Erythropoietin,EPO). The muscle tissue of the apical region was taken and fixed with formaldehyde, then embedded in paraffin and made into sections. The pathological changes were observed after HE staining. Results: (1) both hypoxic preconditioning and distant ischemic preconditioning had good myocardial protection. Compared with the model group, the symptoms of heart failure in HP group and RIP group were significantly alleviated. The ECG showed that J point elevation was not obvious, CK-MB,cTnT,MDA was decreased, SOD was increased, EPO in HP and RIP group was lower than that in model group. The arrhythmia score was also lower than that in the model group. The ultrastructural results of myocardial pathological sections showed that compared with the control group, myocardial infarction area decreased, myocardial cell edema and degeneration decreased, and the structure was clearer. (2) there was no significant difference in arrhythmia score between HP group and RIP group (P0.05), CK-MB,cTnT,SOD,. The level of MDA was higher than that of RIP, and EPO was significantly higher than that of RIP. There was no statistical difference in symptoms of heart failure. The pathological structure showed that myocardial cell injury was a little more serious than RIP, the infarct area was larger, and neovascularization could be seen in myocardial tissue. Conclusion: (1) hypoxia preconditioning and distant ischemic preconditioning can provide significant myocardial protection for acute myocardial ischemia. (2) hypoxia preconditioning can reduce myocardial injury markers and myocardial ultrastructure. (3) both RIP group and HP group were in CK-MB,. There was significant difference in cTnT (P0.01).
【学位授予单位】：川北医学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R654.1

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