摘要:
To explore the effect and underlying mechanisms of resistance training on cardiac function and structure and function of myocardial mitochondria in aged rats.Establishing resistance training model of aged rats,the rats were divided into three groups:young control group (y-Ctrl),elderly control group (e-Ctrl) and elderly resistance training group (e-RT).We detected heart coefficient and haemodynamics parameters of rats,and observed myocardial morphological change and myocardial mitochondrial structure change of rats.The expressions of PGC1α,SIRT1,AMPKα1,AMPKα2 were measured in myocardium of rats.Compared with eCtrl,the heart coefficient was increased significantly in rats of e-RT,while haemodynamics parameters,including left ventricular systolic pressure,left ventricular end-diastolic pressure,the maximal ascending rate of left ventricular pressure,and the maximal descending rate of left ventricular pressure,all were reduced dramatically in rats of e-RT.Resistance training enhanced number of aged cardiocytes to make its arrangement and distribution more closely,and alleviated content of collagen fiber in myocardium of aged rats.Compared with eCtrl,the expressions of PGC1α,SIRT1,AMPKα1,AMPKα2 were improved remarkably in myocardium of rats of e-RT.Long-term resistance training can improve aged cardiac function,and reduce systolic and diastolic pressure of aged rats.In addition,it can protect structural integrality of myocardium and myocardial mitochondria,the underlying mechanisms are associated with AMPK/PGC1α/SIRT1 signaling pathway to improve myocardial mitochondrial function of aged rats.Resistance training can be regarded as an economical and safe method for preventing and delaying senescence.%探讨抗阻力运动对衰老的大鼠心功能及心肌线粒体结构功能影响的机制.建立老年大鼠的抗阻力运动模型,实验分为3组:青年对照组(y-Ctrl),老年对照组(e-Ctrl)和老年抗阻力运动组(e-RT).检测大鼠心系数、血流动力学指标,观测大鼠心肌的形态学变化以及心肌线粒体结构的改变.检测大鼠心肌PGC1α,SIRT1,AMPKα1,AMPKα2的表达.与e-Ctrl组相比,e-RT组大鼠的心系数显著提高,而左室收缩压、左室舒张末压、左室压力最大上升速率和最大下降速率等血流动力学指标都显著下降.抗阻力运动提高衰老的心肌细胞的数量,使心肌细胞排列和分布更加紧密,并且可以减少胶原纤维的含量.与e-Ctrl组相比,e-RT组大鼠心肌的PGC1α,SIRT1,AMPKα1,AMPKα2的表达显著增加.长期抗阻力运动可以改善衰老的心功能,降低老年大鼠的收缩压和舒张压,保护心肌以及心肌线粒体结构的完整性,可能通过AMPK/PGC1α/SIRT1信号通路改善老年大鼠的心肌线粒体功能.抗阻力运动可作为老年人预防和延缓衰老的一种经济安全的方法.