中文摘要：

目的观察不同时间实施电针预处理对大鼠心肌缺血损伤的影响及该影响与心肌HIF-1α表达的相关性。方法54只雄性SD大鼠随机分为模型组（MI）、电针1d组（EA-1d）、电针2d组（EA-2d）、电针3d组（EA-3d）、电针4d组（EA-4d）、电针5d组（EA-5d），每组9只。选择大鼠双侧内关穴进行电针干预后，结扎心脏冠状动脉左前降支（LAD）建立急性心肌缺血模型，进行心电图检测，并于24h后取心脏，采用TTC染色评价效应差异，采用Westernblot技术检测HIF-1α表达，并在明确最佳时间点后，增设假手术组（Sham）和假手术加电针组（Sham＋EA），每组3只，进一步观察HIF-1α表达情况。结果MI组结扎LAD30min后，ST段弓背抬高，结扎24h后出现病理性Q波，提示模型制作成功；与MI组比较，EA-ld、EA-2d组心肌梗死面积变化无统计学意义，HIF-1α蛋白表达无统计学意义；EA-3d、EA-4d和EA-5d组心脏梗死面积比明显减小（P〈0．05），HIF-1α蛋白表达水平增加（P〈0．01），但3组间变化无统计学意义；电针预处理4d的Westernblot结果显示，与Sham组比较，MI组HIF-1α蛋白表达水平显著下降（P〈0．05），电针预处理能使MI下降的HIF-1α表达上升（P〈0．05）。结论电针预处理内关穴3～5d均能有效降低心肌梗死面积，其中以4d为佳，该保护效应与调控HIF-1α蛋白密切相关。

英文摘要：

OBJECTIVE To observe the effect of eleetroacupuncture pretreatment on myocardial ischemia injury at different time, and the correlation between the effect and the expression of HIF-1α. METHODS 54 Male SD rats were randomly divid- ed into model group（MI）, electroacupuncture 1 d group（EA-ld）, electroacupuncture 2 d group（EA-2d）, electroacupuncture 3 d group（EA-3d）, electroacupuncture 4 d（EA-4d） and electroacupuncture 5 d group（EA-5d）. After pretreatment with electroa- cupuncture in rats with bilateral Neiguan points for 1,2,3,4,5 d in each group, respectively, acute myocardial ischemia model was established by ligation of the left anterior descending（LAD） branch of coronary artery. ECG was detected, the heart was collected and the TTC staining was used to evaluate the effect difference after 24 h. Western blot experiments were performed to detect the expression of HIF-1α protein. After finding the best point of time, sham operated group （Sham, n=3） and sham operation with EA group（Sham＋EA, n =3） were established to investigate the expression of HIF-1α. RESULTS ECG results showed that compared with Sham group, the MI group ST-segment elevated after ligation of the LAD. After the ligation of 24 h, a pathological O wave appeared, which suggested that the model was successful. Compared with the MI group, the myocar dial infarction area ratio and the expression of HIF-1α protein of EA-ld and EA-2d groups showed no difference（P〉0.05）. Compared with the MI group, the myocardial infarction area ratio of EA-3d, EA-4d and EA-Sd groups significantly decreased （P〈0.05）, and the expression of HIF-1α protein significantly increased（P〈0.01）, but no difference was found among the 3 groups（P〈0.05）. The optimal electroacupuncture pretreatement time was 4 d. Western blot results showed that the HIF-1α protein expression levels of MI group decreased compared with sham group（P〈0.05）. And the electroacupuncture pretreat- ment increased the expression of HIF-1α pr