尼可地尔减轻大鼠心肌缺血再灌注损伤作用的研究

发布时间：2018-12-19 16:06

【摘要】：目的:尼可地尔是钾离子通道(ATP sensitive K+channel,KATP)开放剂,临床已经广泛用于治疗缺血性心脏病。当前已有研究运用尼可地尔治疗心肌缺血再灌注损伤(myocardial ischemia reperfusion injury,MIRI),但其作用机制尚不清楚。本研究拟探讨尼可地尔急性预处理抑制MIRI的作用机制。方法:将75只雄性SD大鼠,运用随机数字表法,随机分为假手术组、生理盐水组、尼克地尔A组、尼克地尔B组、尼克地尔C组,每组15只。通过手术结扎大鼠冠状动脉左前降支(left anterior descending coronary arteries,LAD),建立大鼠MIRI模型,假手术组只穿线不结扎,缺血30分钟后,尼可地尔组尾静脉注射0.2 mL尼可地尔,假手术组和生理盐水组尾静脉0.2 m L生理盐水,然后再灌注120分钟。其中,尼可地尔A、B、C组分别给予尼可地尔2.5 mg/kg、5.0 mg/kg、10.0 mg/kg。再灌注结束后取材,腹主动脉采血取血清,检测肌酸激酶同工酶(CK-MB)、肌钙蛋白I(cTn I)、肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)、超氧化物歧化酶(SOD)、丙二醛(MDA)、一氧化氮(NO)、内皮素-1(ET-1)水平;采血后取心脏,苏木精-伊红(hemotoxylin and eosin,HE)染色观察左心室心肌组织病理学改变;2,3,5—氯化三苯基四氮唑(2,3,5-triphenyltetram lium chloride,TTC)染色检测心肌梗死面积。结果:与假手术组比较,生理盐水组和尼可地尔组大鼠血清CK-MB、cTnI、TNF-α、IL-1β、MDA、ET-1水平升高,NO、SOD水平降低,差异有统计学意义(P0.05);与生理盐水组比较,尼可地尔组大鼠血清CK-MB、c TnI、TNF-α、IL-1β、MDA、ET-1水平降低,NO、SOD水平升高,差异有统计学意义(P0.05);尼可地尔组间比较,B、C组CK-MB、cTnI、TNF-α、IL-1β、MDA、ET-1水平低于A组,NO、SOD水平高于A组,差异有统计学意义(P0.05),而B、C组之间比较差异无统计学意义(P0.05)。TTC染色结果显示尼可地尔组心肌梗死面积小于生理盐水组,差异具有统计学意义(P0.05);尼可地尔组间比较,B、C组梗死面积小于A组,差异有统计学意义(P0.05),而B、C组之间差异无统计学意义(P0.05)。HE染色结果显示假手术组心肌细胞排列整齐,包膜完整,横纹清晰,细胞核呈椭圆形;生理盐水组心肌细胞排列不整齐,横纹不清晰,细胞水肿,心肌纤维间大量炎细胞浸润,可见细胞核固缩;尼可地尔A、B、C组也有心肌细胞排列不整齐,横纹不清晰的表现,但程度较轻,心肌纤维间可见不同程度炎细胞浸润。结论:尼可地尔单次急性预处理抑制MIRI,它能减少心肌梗死面积,减轻氧化应激、炎症损伤,保护内皮功能。其中5mg/kg是较为理想的尼可地尔注射剂量,能够较大程度地发挥其抗再灌注损伤的作用。其作用机制可能与尼可地尔具有硝酸盐特性有关。
[Abstract]:Objective: nicorandil is a potassium channel (ATP sensitive K channel,KATP opener and has been widely used in the treatment of ischemic heart disease. Nicorandil has been used in the treatment of myocardial ischemia reperfusion injury (myocardial ischemia reperfusion injury,MIRI), but its mechanism is not clear. The aim of this study was to investigate the mechanism of acute pretreatment of nicorandil on inhibition of MIRI. Methods: 75 male SD rats were randomly divided into sham operation group, normal saline group, Nexidil A group, Nexidil B group and Nexidil C group with 15 rats in each group. Rat model of MIRI was established by ligating left anterior descending branch of coronary artery (left anterior descending coronary arteries,LAD). After 30 minutes of ischemia, nicodil was injected into the tail vein of nicorandil group with 0.2 mL nicodil. The caudal vein of sham-operated group and saline group was 0.2 mL saline, then perfused for 120 minutes. In group C, nicorandil was given for 2.5 mg/kg,5.0 mg/kg,10.0 mg/kg., respectively. After reperfusion, serum samples were collected from abdominal aorta. Creatine kinase isoenzyme (CK-MB), troponin I (cTn I), tumor necrosis factor- 伪 (TNF- 伪), interleukin-1 尾 (IL-1 尾) were detected. Superoxide dismutase (SOD), malondialdehyde (MDA), nitric oxide (no), (NO), endothelin-1 (ET-1); The left ventricular myocardial histopathological changes were observed by hematoxylin and eosin (hemotoxylin and eosin,HE staining, and myocardial infarction size was detected by 2-titriphenyltetramethyl lium chloride,TTC staining. Results: compared with sham operation group, the serum levels of CK-MB,cTnI,TNF- 伪, IL-1 尾, MDA,ET-1 in normal saline group and nicorandil group were increased and NO,SOD level was decreased (P0.05). Compared with normal saline group, the serum levels of CK-MB,c TnI,TNF- 伪, IL-1 尾, MDA,ET-1 in nicorandil group decreased and NO,SOD level increased (P0.05). The levels of CK-MB,cTnI,TNF- 伪, IL-1 尾, MDA,ET-1 in group B C were lower than those in group A, and NO,SOD levels were higher than those in group A (P0.05). There was no significant difference between group C (P0.05). TTC staining results showed that the size of myocardial infarction in nicorandil group was smaller than that in saline group, the difference was statistically significant (P0.05); The infarct size in group B C was smaller than that in group A (P0.05), but there was no significant difference between group B and C (P0.05). HE staining showed that myocardial cells were arranged neatly in sham operation group. The capsule was intact, the striation was clear and the nucleus was elliptic. In the saline group, the myocardial cells were not arranged neatly, the striations were not clear, the cells were edema, a large number of inflammatory cells were infiltrated between the myocardial fibers, and the nuclei were pyknosis. In group C, the arrangement of cardiomyocytes was irregular, the striation was not clear, but the degree was light, and inflammatory cell infiltration could be seen in different degree between myocardial fibers. Conclusion: single acute pretreatment with nicorandil can reduce myocardial infarction size, reduce oxidative stress, inflammatory injury and protect endothelial function. Among them, 5mg/kg is an ideal dose of nicorandil, which can play an important role in anti-reperfusion injury. The mechanism may be related to the nitrates of nicordil.
【学位授予单位】：湖北医药学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R542.22

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