大豆异黄酮预防离体大鼠心肌缺血再灌注损伤

Effects of soy isoflavones preconditioning on myocardial ischem ia/reperfusion injury in isolated hearts of rats

目的:观察大豆异黄酮(SI)预处理对离体大鼠心肌缺血再灌注损伤的影响。方法:应用Langendorff灌注大鼠离体心脏,停灌/复灌方式制备缺血再灌注模型。SD雄性大鼠40只,随机分为正常对照组、缺血再灌注组(I/R)、低剂量SI组(L-SI)、中剂量SI组(M-SI)、高剂量SI组(H-SI),L-SI、M-SI、H-SI组分别予SI 30、60、120mg.kg-1.d-1灌胃,第15天末采集心脏收缩期左心室内压上升的最大变化速率(+LVdp/dtmax)、舒张期左心室内压下降的最大变化速率(-LVdp/dtmax)及左室发展压(LVDP)、左心室舒张末压(LVEDP)及心率与发展压的乘积(RPP)并分析;电镜观察心肌细胞超微结构改变。结果:与正常对照组比较,I/R组LVEDP明显升高(P<0.01);LVDP,+dp/dtmax,-dp/dtmax,RPP均明显降低(P<0.05,P<0.01)。与I/R组比较,M-SI组LVEDP明显降低(P<0.01),RPP明显升高(P<0.05)。与I/R组比较,H-SI组LVDP、+dp/dtmax、-dp/dtmax均明显升高(P<0.05,P<0.01)。I/R组中,心肌纤维断裂,线粒体肿胀,嵴破坏消失,此变化在M-SI、H-SI预处理组中明显减轻。结论:中、高剂量SI对离体缺血再灌注大鼠受损伤的心肌有保护作用。

AIM：To observe the influence of soy isoflavones preconditioning on ischemia/reperfusion injury（IRI） in isolated hearts in rats. METHODS：The ischemia/reperfusion（I/R） model of isolated perfused hearts was established by stopping and reperfusing Krebs-Henseleit（KH） fluid to the hearts of the rats.Forty SD rats were randomly divided into five groups：control group,ischemia/reperfusion group（I/R）,three SI treatment groups（L-SI,M-SI,H-SI）.0.5%CMC-Na were given in I/R group,SI 30,60,120 mg·kg-1·d-1 were given in L-SI,M-SI,H-SI groups.After 15 days,the changes of maximal rate of the pressure（＋LVdp/dtmax） increase,maximal rate of the pressure（-LVdp/dtmax） decrease,left ventricular developed pressure（LVDP）,left ventricular end-diastolic pressure（LVEDP）of heart,and rate-pressure product（RPP） were observed and analysis.The ultrastructure of heart cells were oberserved by electron micronscopy. RESULTS：Compared with control group,the level of LVEDP was increased obviously in I/R group（P0.01）,the levels of LVDP,＋dp/dtmax,-dp/dtmax,RPP were decreased（P0.05,P0.01）.Compared with I/R group,the level of LVEDP was decreased obviously in M-SI group（P0.01）,the level of RPP was increased（P0.05）.Compared with I/R group,the levels of LVDP,＋dp/dtmax,-dp/dtmax were increased in H-SI group（P0.05,P0.01）.In I/R group,the mitochondria was swelling,myocardium muscle fibers was breaked and the iliac crest destruction was disappeared,the above changes were reduced obviously in M-SI,H-SI groups. CONCLUSION：M-SI,H-SI behave a protective effect on ischemia/reperfusion inisolated rat hearts.