The Effect Of ST-1 Intragastric Administration Against Myocardium Injury Induced By Ischemia-Reperfusion In Rats And The Primary Study Of Mechanism

Object: The study is designed to demonstrate experimently the cardioprotective effect of ST-1 intragastric administration(ig) against myocardium injury induced by ischemia- reperfusion in anesthetized rats,and to compare the effect with six ramifications of stevioside.Methods: The SD rats are used for the experiment and anesthetized (urethane 1.0 g·kg-1,ip),and the experimental animals are divided into sham operation group(SO), ischemia-reperfusion group(IR), ST-1 pretreated group, Guanxin Danshen Pian pretreated group, and the ramifications of stevioside pretreated group,12 rats per group. The SO group ,a silk suture is passed through the myocardium beneath a main branch of the left coronary artery and rats are observed for 120 min.The rest groups ,the left coronary artery is occluded lasting for 30 min followed by reperfusion for 90 min in rats.Pretreatments are performed by 60 min prior to ischemia. The hemodynamics changes(MAP,LVSP,LVEDP,LVDP',±dp/dtmax,et al) and arrhythmias (ventricular tachycardia,VT and fibrillation,VF) are determined during ischemia-reperfusion. The serum lactate dehydrogenease(LDH) and creatine kinase(CK) activities are assayed at the end of the reperfusion. Myocardial microstructure and the activities of NFκB,Bcl-2 and COX-2 are examined to evaluate the cardioprotective effect.Results: The values of hemodynamics in the groups of pretreatment with ST-1 and Guanxin Danshen Pian are significantly higher than those in IR group . There are no significant changes on heart rate and mean arterial blood pressure by administration of ST-1. The activities of serum LDH and CK,and the incidences of ventricular tachycardia(VT) and ventricular fibrillation(VF) are less than those in IR group. The myocardial microstructure and the activities of NFκB,Bcl-2 and COX-2 show myocardial injury in ST-1 pretreatment group is better than those in IR group.The ramifications of stevioside pretreatment group don't show the same cardioprotective effect as ST-1.Conclusion: The result is suggested that pretreatment with ST-1 ig has cardioprotective effect against ischemia-reperfusion injury in anesthetized rats,and it may be mediated by antiinflammation and antiapoptosis.