Establishment of a Standard Acute Myocardial Infarction Model for Cellular Transplantation Research in Rats

Objective To explore the feasibility of establishment of acute myocardial infarction(AMI) models induced by occlusion of left anterior descending coronary artery(LAD),which provide a reliable model for the study of repair myocardial infarction by cellular transplantation in rat.Methods Fourteen adult Sprague-Dawley(SD)rats with respirator were established by ligating the middle-proximal 1/3 segment of left anterior descending coronary artery(LAD) in AMI model group.Continuous electrocar- diographic monitoring were performed both before the LAD ligating and after the LAD ligated by multiple peripheral adapter(MPA)multichannel physiologic recorder system.The cardiac function indicated by these parameters of left ventricular systolic pressure(LVSP),left ventricular end-diastolic pressure (LVEDP)and±dp/dtmax were observed by multipurpose polygraph of langendorff perfusion of the isolated heart methods,and their pathological morphology,myocardial infarction size(MIS)and mortal- ity were detected and analyzed four weeks after LAD occlusion to see whether there were any tissue necrosis and its extension.Other ten adult SD rats without ligating coronary artery as control group. Results The survival rate of the treated rats was 71.43%(10/14)beyond four weeks.After LAD ligation,electrocardiogram displayed ST elevated continuously immediately and pathologic Q wave after ligating 30 min.Pathologic examination suggested myofibers chaotically arranged,myofilament ruptured or lysed,nuclei pyknosis and fragmentation,interstitial hyperemia and edema,infiltration of inflammatory cells,necro-myocardium were superseded by fibrous tissue.Meanwhile,the cardiac function observa- tion indicated by these parameters of LVSP,LVEDP and±dp/dtmax descend markedly in LAD occlusion rats after ligating four weeks late.MIS were invariableness in AMI model group(44.38%±8.04%).Conclusion A standard rat AMI model could be created by surgical ligation of LAD,and the model would be suitable for the research on cellular transplantation.