白藜芦醇对心肌缺血再灌注过程中线粒体的保护

目的:探讨白藜芦醇对心肌缺血再灌注损伤过程中Ca²⁺-ATPase及HSP70表达的影响。方法:健康雄性SD大鼠40只,采用随机数字量表法分为4组(假手术组、缺血再灌注组、缺血预适应组、白藜芦醇组),采用结扎冠状动脉前降支制备心肌缺血再灌注损伤模型,于结扎前15 min及再灌注前1 min经舌下静脉注射白藜芦醇10 mg·kg^-1。提取心肌线粒体,紫外可见光分光光度计测定线粒体中SDH、Na⁺-K⁺-ATPase、Ca²⁺-ATPase活性;荧光分光光度计测定线粒体中游离钙、mPTP开放度及跨膜电位;RT-PCR及Western blot检测心肌组织HSP70、Ca²⁺-ATPase mRNA及蛋白质的表达。结果:白藜芦醇与缺血再灌注组及缺血预适应组相比,线粒体中SDH、Na⁺-K⁺-ATPase、Ca²⁺-ATPase的活性明显提高(P<0.05或P<0.01);线粒体内钙离子浓度明显下降(P<0.05或P<0.01)、mPTP开放程度减小(P<0.01)、线粒体膜电位增高(P<0.01);Ca²⁺-ATPase、HSP70在 mRNA或蛋白水平上的表达均有所增加(P<0.05或P<0.01)。结论:白藜芦醇可能通过增加心肌组织中Ca²⁺-ATPase、HSP70 mRNA和蛋白的表达,提高线粒体Ca²⁺-ATPase的活性,产生对大鼠心肌缺血再灌注损伤时线粒体的保护作用。

Protective effects of resveratrol on mitochondria during myocardial ischemia reperfusion

OBJECTIVE To investigate effects of resveratrol on expression of Ca²⁺-ATPase and HSP70 during myocardial ischemia reperfusion injury. METHODS Forty male SD rats were randomly divided into 4 groups (sham operation group, ischemia reperfusion group, ischemic preconditioning group, resveratrol group). Myocardial ischemia reperfusion injury model was induced by ligating anterior descending branch of coronary artery, from where resveratrol of 10 mg·kg^-1 was intravenously injected before ligation of 15min and reperfusion of 1min. Activities of succinate dehydrogenase, Na⁺-K⁺-ATPase and Ca²⁺-ATPase in mitochondrion were determined by UV visible spectrophotometer while myocardial mitochondria was extracted. Free calcium, mPTP openness and transmembrane potential of mitochondrion were determined by fluorescence spectrophotometer. The mRNA expression and protein expression of HSP70 and Ca²⁺-ATPase in cardiac tissues were detected by RT-PCR and Western blot, respectively.RESULTS Resveratrol could increase activities of succinate dehydrogenase, Na⁺-K⁺-ATPase and Ca²⁺-ATPase in mitochondrion, decrease free calcium and mPTP openness, and increase transmembrane potential. Changes of the above data were accompanied with increase of expressions of mRNA and protein of HSP70 and Ca²⁺-ATPase in cardiac tissues. CONCLUSION Our data suggest that resveratrol may protect mitochondria during myocardial ischemia reperfusion injury, which is accompanied with increased expressions of mRNA and protein of Ca²⁺-ATPase and HSP70, and improve mitochondrial Ca²⁺-ATPase activity.