The Protective Effect Of Sheng Mai Injection On Acute Myocardial Infarct In Dogs

The incidence rate of ischemic heart disease is increasing with theelevating living standard and extending life expectancy in all the world.The coronary disease is harmful to people's health. The primary cause ofangina pectoris is an imbalance between the oxygen requirement of heartand the oxygen supplied to it via the coronary vessels. Acute myocardialinfarction(AMI) will occurred when coronary vessels suddenly reduce ordiscontinue blood supply to the heart, which caused severe ischemia ornecrosis in myocardium. The patients with AMI is commonly experiencedas a heavy, pressing substernal pain in combination with S-T elevatedsignificantly in electrocardiograph and the level of myocardium enzymeincreasing, moreover, AMI may be associated with an increased risk ofcardiac dysrhythmia, cardiac shock and cardiac failure. Developingcompound recipe of traditional Chinese medicine to treat myocardialischemia is a significant field in pharmacological research.Sheng –Mai injection(SMI) which is extracted from ginseng,ophiopogonis tuber and Chinese magnoloavine fruit by moderntechnology contains most effective material such as panaxoside,ophiopogonone and lignanoid etc. The study investigates the effect of SMIon the area and degree of myocardial infarct, myocardial enzymology,cardiac oxygen metabolism and hemodynamics by ligation of left anteriordescending artery of the anesthelized open chest dogs and indicates the mechanismof the protective effect.30 dogs were randomly divided into 5 groups(6 dogs in each group ), they aremodel group(5% glucose), positive control group(DML 3.0g/kg), SMI high-dosegroup((4.80g/kg)), SMI median-dose group (2.4g/kg)and SMI low-dosegroup(1.2g/kg). All medicine were administrated by intravenous drop infusion in 90minutes. Dogs were anesthetized with 3% pentobarbital sodium and fixed on theoperation table, then trachea cannula, right common carotid artery cannula, rightfemoral vein cannula and left ventricle cannula were be operated respectively. Heartwas exposed and left anterior descending coronary artery was ligated. Systolic bloodpressure(SBP), diastolic blood pressure(DBP), cardiac output(CO), coronary bloodflow(CBF), left ventricular systolic pressure(LVSP), left ventricular end-diastolicpressure(LVEDP), maximum left ventricular rise rate and maximum left ventricularfall rate(±dp/dtmax) were determined by RM-6000 physical recorder andMFV-3200 electromagnetic flow meter. ECG of standard Ⅱ, epicardiumelectrocardiogram(EECG)and heart rate were recorded at the same time。We cancalculate sroke volume(SV),cardiac index(CI), stroke index(SI), left ventricularwork(LVW), myocardial blood flow(MBF), coronary vascular resistance(CAR)andtotal peripheral resistance (TPR) by the above hemodynamics data. Myocardialinfarction square and myocardial enzymology were determined at the end of eachexperiment. SMI can reduce the degree of myocardial ischemia and decrease myocardialinfarction square in the dosage of 4.8g/kg, 2.4g/kg and 1.2g/kg and dose-effectrelationship is clear. SMI can decrease the activity of LDH, CK and AST. The resultsshowed that SMI has the protective effect on myocardial cell in the condition ofischemia and anoxemia.