目的通过对心肌缺血实验性指标的测定,筛选出小红参不同溶剂提取物中抗心肌缺血的主要活性部位,并研究其抗垂体后叶素(Pit)致心肌缺血的活性。方法通过小鼠常压耐缺氧试验、二磷酸腺苷(ADP)诱导家兔体外血小板聚集影响试验、去甲肾上腺素(NE)诱导大鼠离体主动脉环收缩试验,比较小红参石油醚、乙酸乙酯、正丁醇、水4种溶剂提取物抗心肌缺血的活性强度,以确定其抗心肌缺血活性的主要部位,再进行小红参主要活性部位抗Pit致大鼠心肌缺血的活性研究。结果小红参乙酸乙酯提取物在各试验中均有明显活性,并在NE诱导大鼠离体主动脉环收缩试验中对动脉环的舒张效应明显较强;还能明显对抗Pit所致心肌缺血大鼠心电图第1期和第2期的T波抬高(P<0.01),且能明显增强超氧化物歧化酶(SOD)活性、降低丙二醛(MDA)含量。结论小红参乙酸乙酯提取物为其抗心肌缺血的主要活性部位,能够对抗由Pit引起的大鼠急性心肌缺血。 Objective To determine the main active site of anti-myocardial ischemia in different solvent extracts of small red ginseng through the determination of experimental indicators of myocardial ischemia, and to study its anti-ischemia activity induced by pituitrin (Pit). METHODS: Mouse hypoxia-tolerance hypoxia test, adenosine diphosphate (ADP)-induced rabbit platelet aggregation test in vitro, norepinephrine (NE)-induced rat aortic ring contraction test, and comparison of small red ginseng oil Ether, ethyl acetate, n-butanol, water extracts of four solvents anti-ischemic activity intensity to determine the main site of its anti-ischemic activity, and then the main active site of small red ginseng anti-Pit induced rat myocardium Ischemia activity studies. Results The ethyl acetate extracts of red ginseng showed significant activity in all experiments. The relaxation effect on the aortic rings was significantly stronger in NE-induced rat aortic ring contraction test; it also significantly counteracted Pit-induced myocardium. T-wave elevation in the first and second phases of the ischemic rat electrocardiogram (P<0.01) increased the activity of superoxide dismutase (SOD) and decreased malondialdehyde (MDA) content. Conclusion Ethyl acetate extract of red ginseng is the main active site against myocardial ischemia and can counter the acute myocardial ischemia induced by pit in rats.