中文摘要：

目的：探讨钾通道开放剂尼可地尔对离体大鼠心肌缺血再灌注损伤（MIRI）的影响。方法：建立Langendorff离体心脏灌流系统,44只大鼠随机分为4组：正常组、缺血再灌注组（I-R组）、腺苷（100μmol/L）缺血再灌注组（A/I-R组）、尼可地尔（200μmol/L）缺血再灌注组（N/I-R组）,每组11只。分别记录并分析各组左心室发展压（LVDP）、左心室内压力最大上升/下降速率（±dp/dt_（max））、再灌注心律失常（RA）、心肌梗死面积以及左心室心肌组织的乙醛脱氢酶2（ALDH2）、抗凋亡基因B淋巴细胞瘤-2（Bcl-2）以及促凋亡基因B淋巴细胞瘤-2相关x蛋白（Bax）的表达水平。结果（：1）N/I-R组再灌注30 min与再灌注45 min的LVDP均高于I-R组与A/I-R组（P均〈0.05）。（2）I-R组再灌注30 min及45 min的±dp/dt_（max）均低于N/I-R组和A/I-R组（P均〈0.05）。N/I-R组再灌注30 min及45 min的±dp/dtmax均高于A/I-R组（P均〈0.05）。（3）与I-R组比较,N/I-R组和A/I-R组的RA评分均降低（P均〈0.01）。N/I-R组与A/I-R组差异无统计学意义（P=0.771）。（4）N/I-R组和A/I-R组心肌梗死面积均低于I-R组（P均〈0.01）,N/I-R组心肌梗死面积最小（P〈0.05）。（5）与正常组比较,I-R组线粒体ALDH2表达明显减少,Bcl-2、Bax的表达增加;N/I-R组线粒体ALDH2表达增加,A/I-R组表达减少,N/I-R组和A/I-R组的Bcl-2、Bax的表达均增加。与I-R组比较,N/I-R组以及A/I-R组Bcl-2/Bax的比值均增大（P均〈0.05）;在抗凋亡方面N/I-R组与A/I-R组差异无统计学意义（P〉0.05）。结论：尼可地尔可以减少MIRI,对心肌起到保护作用,其总体作用效果优于腺苷。尼可地尔可上调线粒体ALDH2、Bcl-2表达以及下调Bax的基因蛋白的表达。

英文摘要：

Objective： To investigate the effect of potassium channel opener nicorandil on myocardial ischemia-reperfusion injury（MIRI） in isolated rat＇s heart. Methods： Langendorff system was established for isolated heart reperfusion. A total of 44 rats were randomly divided into 4 groups： Normal control group, Ischemia-reperfusion（I-R） group, Adenosine/I-R（A/I-R） group, the I-R heart was treated by adenosine 100 μmo/L and Nicorandil/I-R（N/I-R） group, the I-R heart was treated by nicorandil 200 μmo/L. n=11 in each group. Left ventricular developed pressure（LVDP）, the maximal rise/fall rate of left ventricular pressure（±dp/dtmax）, reperfusion arrhythmia（RA） and myocardial infarction（MI） size were recorded; the expressions of left ventricular tissue acetaldehyde dehydrogenase 2（ALDH2）, Bcl-2 and Bax were examined and compared among different groups.Results：（1） Compared with I-R and A/I-R groups, N/I-R group had increased LVDP at 30 min and 45 min reperfusion, all P 0.05.（2） Compared with N/I-R and A/I-R groups, I-R group showed reduced ±dp/dtmax at 30 min and 45 min reperfusion, all P〈0.05; while ±dp/dtmax in N/I-R group was higher than A/I-R group at 30 min and 45 min reperfusion, all P〈0.05.（3） Compared with I-R group, both N/I-R and A/I-R groups presented reduced RA score, all P〈0.01, RA score wassimilar between N/I-R group and A/I-R group, P=0.771.（4） compared with I-R group, both N/I-R and A/I-R groups had the smaller MI size, P〈0.01 and N/I-R group showed the smaller MI size, P〈0.05.（5） Compared with Normal control group, I-R group had decreased mitochondrial ALDH2 expression and increased Bcl-2, Bax expression; ALDH2 level was elevated in N/I-R group had reduced in A/I-R group; Bcl-2 and Bax levels were increased in both N/I-R and A/I-R groups. Compared with I-R group, both N/I-R and A/I-R groups had increased ratio of Bcl-2/Bax, P〈0.05; the anti-apoptosis effect was similar between N/I-R group and A/I-R group, P〈0.05. Conclusion： N