天麻多糖对垂体后叶素致急性心肌缺血大鼠的保护作用

目的：研究天麻多糖（polysaccharides from gastrodia elata B1，GBP）对大鼠心肌缺血的保护作用，并探讨其可能的作用机制。方法：采用大鼠舌下静脉注射垂体后叶素注射液（0．5U·kg^-1）造成急性心肌缺血模型，观察各组大鼠心电图和血清超氧化物歧化酶（superoxide dismutase，SOD）、乳酸脱氢酶（1actate dehydrogenase，LDH）、肌酸激酶（creatine kinase，CK）和丙二醛（malonaldehyde，MDA）变化差异。结果：天麻多糖可能显著降低垂体后叶素致急性心肌缺血大鼠的心电T波变化值，提高大鼠血清SOD活性，抑制血清中CK、LDH活性，显著降低脂质过氧化物MDA水平，且这些作用呈现一定的剂量依赖关系。结论：天麻多糖可提高大鼠心肌耐缺氧能力，对垂体后叶素致急性心肌缺血大鼠的心肌缺血性损伤具有一定的保护作用，其机制可能与其减轻心肌膜过氧化损伤和降低缺血性心肌酶释放有关。

Protective Effects of Polysaccharides from Gastrodia Elata BI on Pituitrin-induced Acute Myocardial Ischemia in Rats

OBJECTIVE To study the protective effects of Polysaccharides from Gastrodia Elata B1 （GBP）on pituitrin-induced acute myocardial ischemia in rats and the possible mechanisms. METHODS： The acute myocardial ischemia in rat was induced by injection of pituitrin （0.5 U·kg-1 ） via ranine vein. The changes in ECG and the levels of superoxide dismutase （SOD） , lactate dehydrogenase （LDH） , creatine kinase （CK） and malonaldehyde （MDA） in serum were observed. RESULTS： GBP markedly inhibited the pituitrin-induced raise of T2-waves in myocardial ischemia rat, up-regulated the activity of SOD, inhibited the activities of CK and LDH and down-regulated MDA level in dose-dependent manner. CONCLUSION： GBP can enhance the tolerance of rat myocardium to hypoxia and protect rat myocardium against ischemic injury to a certain extent. Its mechanism might be related to the attenuation of peroxidative damage of myocardial membrane and the decreased release of ischemic cardiac enzymes.