针灸预处理对不同时间心肌缺血再灌注损伤兔血浆内皮素、血清肌酸激酶和心肌组织热休克蛋白70表达的影响

目的:探讨针灸预处理对心肌缺血再灌注损伤(myocardial ischemia-reperfusion injury,MIRI)兔的心肌预防保护机制。方法:将新西兰大耳白兔随机分为假手术组、模型组、电针预处理组和艾灸预处理组,各组按预处理后造模时间再分3个亚组,每组6只。电针预处理组及艾灸预处理组造模前电针或艾灸"内关",每次20min,每日1次,共治疗5d。各组分别于预处理5d后0、24、48h行冠脉结扎法复制兔心肌缺血再灌注模型。酶联免疫法检测血清肌酸激酶(creatine kinase,CK)及血浆内皮素(endothelin,ET),用免疫组化法检测心肌组织热休克蛋白70(heat shock protein,HSP 70)表达。结果:与假手术组比较,模型组各不同时间段血浆ET含量和血清CK含量明显升高(P0.01,P0.05),HSP 70表达虽有所增强,但差异无统计学意义(P0.05)。与模型组比较,电针预处理24、48h血浆ET含量及血清CK含量均降低(P0.01,P0.05),艾灸预处理48h血浆ET含量降低(P0.01);电针预处理后48h及艾灸预处理后0、24、48hHSP 70表达较模型组显著升高(P0.01,P0.05),其中艾灸24h组HSP 70表达又显著高于电针24h组(P0.01)。结论:电针与艾灸预处理对MIRI均具有预防保护作用,其作用机制可能与血浆ET含量、血清CK含量减少,及心肌组织HSP 70表达增强有关,这种预防保护效果还存在时间的差异,电针与艾灸均具有延迟保护作用。

Effect of Electroacupuncture and Moxibustion Preconditioning on Blood Endothelin and Creatine Kinase Contents and Myocardial HSP 70 Expression in Rabbits with Myocardial Ischemia-reperfusion Injury

Objective To observe the effect of electroacupuncture(EA)and moxibustion(Moxi)preconditioning of bilateral"Neiguan"(PC 6)on plasma endothelin(ET)and serum creatine kinase(CK)contents and myocardial hot shock protein70(HSP 70)expression in myocardial ischemia-reperfusion injury(MIRI)rabbits,so as to revel their mechanisms underlying prevention of myocardial ischemia.Methods A total of 72 New Zealand rabbits were randomly divided into sham operation,MIRI model,EA preconditioning and Moxi preconditioning groups(n=18/group).Each group was further divided into 0h,24 hand 48h(time-point)subgroups(n=6in each subgroup).The MIRI model was established by occlusion of the anterior descending branch of the left coronary artery for 40 min and reperfusion for 60 min.The contents of plasma ET and serum CK were detected by ELISA,and myocardial HSP 70 expression was detected by immunohistochemistry.EA and Moxi preconditioning were respectively applied to bilateral PC 6for 20 min,once daily for 5days.Results Following MIRI,contents of plasma ET and serum CK contents were significantly increased at 0h,24 hand 48hin comparison with the sham group(P<0.01,P<0.05),while myocardial HSP 70 expression at the 3time-points was moderately increased(P>0.05).Compared with the model groups,plasma ET contents at both 24 hand 48hin the EA preconditioning group and at 48 hin the Moxi preconditioning group,CK contents at both 24 hand 48honly in the EA preconditioning group were significantly down-regulated(P<0.01,P<0.05).Myocardial HSP70 expression levels in the EA and Moxi preconditioning groups were considerably up-regulated at the three time-points in comparison with the model group(P<0.05,P<0.01).Conclusion Acupuncture and moxibustion pretreatment may suppress MIRI-induced increase of plasma ET and serum CK and up-regulate myocardial HSP 70 protein expression in MIRI rabbits,suggesting a preventive protection action on ischemic myocardium.