ABSTRACT
ObjectiveTo investigate the effects of postconditioning with Shenmai-injectio on myocardial ischemia-reperfusion (I/R) injury in rats.MethodsThirty-six healthy male SD rats aged 10-12 weeks weighing 240-260 g were randomly divided into 3 groups ( n =12 each):sham operation group (group S) ; myocardial I/R group and Shenmai-injectio postconditioning group (group SPO).Myocardial I/R was produced by ligation of the left anterior descending branch of coronary artery for 30 min followed by 120 min reperfusion in groups I/R and SPO.In group SPO Shenmai-injectio 9 ml/kg was injected iv at the end of 30 min ischemia.Blood samples were collected from abdominal aorta at the end of 120 min reperfusion for determination of serum CK activity and cTnI concentration.The animals were then sacrificed.Myocardial specimens were obtained for microscopic examination,detection of apoptosis and determination of myocardial Bcl-2 and Bax protein expression ( by immuno-histochemis-try).ResultsMyocardial I/R significantly increased serum CK activity,cTnI concentration,apoptotic index (percentage of apoptotic cells) and Bax protein expression and decreased Bcl-2 protein expression in group I/R as compared with group S.Shenmai-injectio postconditioning significantly attenuated I/R-induced above changes and ameliorated histo-pathological damage in group SPO as compared with group I/R.ConclusionShenmai-injectiopostconditioning can reduce myocardial I/R injury by up-regulating Bcl-2 expression and down-regulating Bax expression,leading eventually to reduction in apoptosis.