【摘要】 目的:观察甘蔗叶多糖对大鼠心肌梗死模型24h心电图和心功能的影响及其机制。方法:将健康SD大鼠随机分为实验组、模型组和假手术组,实验组和模型组通过结扎大鼠冠状动脉左前降支（LAD）复制心肌梗死模型,假手术组只开胸不结扎。于术前24h、30min和术后连续4周,实验组灌胃给予甘蔗叶多糖溶液,模型组和假手术组给予等量生理盐水。记录术前、结扎LAD后24h内每间隔1h肢导联（Ⅰ、Ⅱ、aVL）和胸导联（V₁、V₅）心电图,分析ST段偏移情况。术后4周,用心脏彩超测定左室射血分数（LVEF）、左室舒张末期内径（LVEDD）及左心室收缩末期内径（LVESD）,分光光度法检测心肌组织超氧化物歧化酶（SOD）和丙二醛（MDA）含量。结果:术后连续24h,实验组Ⅰ导联、Ⅱ导联及V5导联ST段抬高幅度均明显小于模型组（P<0.05）。与模型组相比,实验组大鼠LVEDD及LVESD明显下降,LVEF显著升高,同时心肌组织SOD活性升高,MDA含量降低,差异均有统计学意义（均P<0.05）。结论:甘蔗叶多糖可改善大鼠心肌梗死24h内的心电图表现及其心功能,其机制可能与提高SOD活性、清除氧自由基、提高机体的抗氧化能力有关。更多还原

【Abstract】 Objective:To investigate the effect and mechanism of sugarcane leaves polysaccharide（SLP）on ST segment of 24 hdynamic electrocardiogram and cardiac function in myocardial infarction（MI）rat model.Methods:SD rats were randomly divided into an experimental group,a control group and a sham-operation group.Rats in the experimental group were administered with SLP via gavage,while those in the control group and sham-operation group were administered with equal volume of saline for 4 consecutive weeks.A rat MI model was established by ligating the left anterior descending（LAD）artery.The limb leads（Ⅰ,Ⅱ,aVL,aVF）and chests leads（V₁,V₅）were monitored before operation and 24 hafter ligation.ST segment deviation was analyzed.Four weeks after operation,left ventricular ejection fraction（LVEF）,left ventricular end-diastolic diameter（LVEDD）and left ventricular end-systolic diameter（LVESD）were measured by echo cardiography.The superoxide dismutase（SOD）activity and malondialdehyde（MDA）content in myocardium were measured by commercial kits.Results:The magnitude of ST segment elevation in leadⅠ,Ⅱand V₅ in the experimental group at 24 hafter LAD ligation was lower than that in the control group（P<0.05）.Compared with control group,MDA level,LVEDD and LVESD in the experimental group were decreased,whereas SOD activity and LVEF were increased（P<0.05）.Conclusion:SLP exerted a protective effect on electrocardiogram and cardiac function in MI rats,and the mechanisms might be related to the elevation of SOD activity,inhibition of oxygen free radicals generation and improvement of the antioxidant capacity.更多还原