碟脉灵注射液对大鼠实验性心肌梗塞的保护作用及其机制

目的：观察碟脉灵注射液（DMLI）对大鼠实验性心肌梗塞的保护作用及其机制。方法：采用大鼠结扎左冠状动脉前降支造成急性心肌梗塞模型，将动物随机分为假手术组、梗塞模型组及DMLI小、中、大剂量组，每组20只大鼠。计算急性心肌梗塞24 h后的心肌梗塞面积（MIS），测定血清天冬酸氨基转移酶（AST）、乳酸脱氢酶（LDH）、肌酸磷酸激酶（CK）、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛（MDA）含量，血浆内皮素（ET）及血管紧张素Ⅱ（AngⅡ）水平，观察全血低、中、高切变率黏度及血浆黏度变化，并测定心肌梗塞及非梗塞区游离脂肪酸（FFA）含量。结果：与梗塞模型组比较，DMLI 中、大剂量组急性心肌梗塞24 h大鼠的MIS缩小（P<0.05或P<0.01），血清AST、LDH、CK活性及MDA降低（P<0.05或P<0.01）， SOD及GSH-Px活性升高（P<0.05或P<0.01），血液黏度、血浆黏度、血浆ET及AngⅡ水平明显下降（P<0.05或P<0.01），心肌梗塞及非梗塞区FFA含量降低（P<0.05或P<0.01）。结论：DMLI对大鼠实验性心肌梗塞具有明显保护作用，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，纠正心肌缺血时FFA代谢紊乱，减少内源性血管活性物质ET及AngⅡ释放以及降低血液黏度等机制有关。

Protective effects of Diemailing Injection on experimental myocardial infarction in rats and its mechanism

Objective To observe the protective effects of Diemailing Injection(DMLI) on experimental myocardial infarction in rats and its mechanism.Methods The experimental myocardial infarction model was induced by left anterior descending coronary occulusion for 24 h in rats.The rats were randomly divided into sham group,myyocardial infaction model group,DMLI groups with different doses(2.5,5.0,10.0 mL·kg~(-1))(n=20).The changes of myocardial infarction size(MIS),aspartate aminotransferase(AST),actate dehydrogenase(LDH),creatine phosphokinase(CK),superoxide dismutase(SOD) and glutathione peroxidase(GSH-Px) activities and malondialdehyde(MDA) content in serum,endothelin(ET) and angiotensinⅡ(AngⅡ) levels in plasma,and low shearing specific viscosity,middle shearing specific viscosity and high shearing specific viscosity of blood and specific viscosity of plasma were determined.At the same time,myocardial free fatty acid(FFA) contents of infarction and noninfarction area were determined.Results In rats treated by DMLI(in doses of 2.5,5.0 and 10.0 mL·kg~(-1) i.v after coronary occulusion),the MIS was significantly reduced(P<0.05 or P<0.01),the AST,LDH and CK activities in serum,the ET and AngⅡ levels in plasma,and viscosity of blood and plasma were declined((P<0.05) or P<0.01),while SOD and GSH-Px activities in serum were increased significantly(P<0.05 or P<0.01).In addition,myocardial FFA contents of infarction and noninfarction area were decreased markedly(P<0.05 or(P<0.01).)Conclusion DMLI has protective effects on experimental myocardial infarction,which may be related to improving myocardial metabolism,increasing the activity of antioxidize,eliminating the free radicals,decreasing ET and AngⅡ levels in plasma,and decreasing blood viscosity etc.