西洋参叶20s-原人参三醇组皂苷对大鼠心肌缺血再灌注损伤的保护作用

目的：观察西洋参叶20s-原人参三醇组皂苷（PQTS）对大鼠心肌缺血再灌注损伤的保护作用，为新药开发提供依据。方法：50只大鼠随机分为假手术组、再灌注模型组及PQTS 12.5、25.0、50.0 mg•kg^-1组（每组10只），PQTS组动物腹腔注射PQTS，假手术组和再灌注模型组注射生理盐水，结扎冠状动脉前降支30 min，松扎再灌注120 min造成心肌缺血再灌注损伤模型，检测各组心肌梗死范围（MIS），血清天冬氨酸氨基转移酶（AST）、乳酸脱氢酶（LDH）、心肌型肌酸激酶同功酶（CK-MB）、超氧物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）活性、丙二醛（MDA）含量、血浆前列环素（PGI₂）及血栓素A₂（TXA₂）水平。结果：与再灌注模型组比较，PQTS 25.0和50.0 mg•kg^-1组MIS缩小（P<0.01），血清AST、LDH、CK-MB活性及MDA含量降低（P<0.01），SOD及GSH-Px活性升高（P<0.05），血浆TXA₂水平下降（P<0.05），PGI₂水平及PGI₂/TXA₂比值增高（P<0.05或P<0.01）。上述指标PQTS 12.5 mg•kg^-1组与对照组及再灌注模型组比较差异无显著性。结论：PQTS对大鼠心肌缺血再灌注损伤具有明显保护作用，可能与其增强抗氧化酶活性、减少自由基对心肌的氧化损伤、纠正血管活性物质平衡失调等机制有关。

Protective effects of panax quinquefolium 20s-protopanaxtriolsaponins on myocardial ischemia-reperfusion injury in rats

Objective To observe the protective effects of panax quinquefolium 20s-protopanaxtriolsaponins(PQTS) on myocardial ischemia-reperfusion injury in rats in order to provide basis for new drug development.Methods Fifty rats were divided randomly into sham group,ischemia-reperfusion model group and PQTS 12.5,25.0 and 50.0 mg·kg-1 group(n=10).All animals in PQTS groups were administered with PQTS one time everyday with intraperitoneal injection(i.p) for 3 d,the rats in sham and model groups were given saline.The myocardial ischemia-reperfusion model was induced by 30 min left anterior descending coronary occulusion and 120 min reperfusion in openchest anesthetized rats.The changes of aspartate aminotransferase(AST),lactate dehydrogenase(LDH),MB isoenzyme of creatine kinase(CK-MB),superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) activities and malondialdehyde(MDA) content in serum,and the prostacycline(PGI2) and thromboxane A2(TXA2) levels in plasma were determined.Results Compared with model group,in rats treated with PQTS (12.5,25.0 and 50.0 mg·kg-1 i.p for 3 d),the MIS was significantly reduced(P<0.01),the AST,LDH and CK-MB activities in serum,the MDA content,and the TXA2 level in plasma were declined(P<0.05 or P<0.01),while the PGI2 level in plasma and PGI2/TXA2 ratio were increased signficatly(P<0.05).In addition,the SOD and GSH-Px activities in serum were increased markedly(P<0.05 or P<0.01).Conclusion PQTS has protective effects on myocardial ischemia-reperfusion injury through enhanceing activity of antioxidase,reducing oxidative damage of free radicals on myocardium and correcting disequilibrium of vasoactive substance.