【摘要】 目的:探讨有氧运动对压力超负荷早期心肌肥厚、心功能及血管新生的影响。方法:8周龄雄性C57BL/6J小鼠分为4组:安静组(CON组),运动组(CE组),压力超负荷组(TAC组)和压力超负荷+运动组(TAE组)。每组15只。TAC组和TAE组施予升主动脉缩窄术(transverse aorta constriction,TAC),术后3天,CE组和TAE组进行2周中等强度跑台运动(10米/分×30分→13米/分×60分,5次/周)。2周后,在采集超声心动图和血流动力学数据后取材,采用免疫组织化学方法检测心肌血管内皮生长因子(vascular endothelial growth factor,VEGF);采用RT-PCR方法检测心肌热休克转录因子(heatshock transcription factor-1,HSF-1)、缺氧诱导因子(hypoxia-inducible factor 1,HIF-1)及VEGFmRNA水平。结果:与CON组相比,TAC组血压升高50 mmHg,说明压力超负荷模型建立成功。与CON组相比,TAC组心肌增厚,心肌微血管增强,射血分数增加(P<0.05),处于代偿期。与CON组相比,CE组射血分数增加,血管新生增加(P<0.05),血管新生相关因子HSF-1、HIF-1和VEGF表达明显增加(P<0.01)。与TAC组相比,TAE组EF值增强(P<0.05),血管新生相关因子HSF-1、VEGF表达增加(P<0.05)。CE组(相对CON组)HSF-1、HIF-1、VEGF表达较CON组的增加幅度大于TAE组较TAC组的增加幅度。HSF-1表达规律与HIF-1、VEGF一致。结论:2周有氧运动有效增强压力超负荷代偿期小鼠心功能及血管新生因子HSF-1、HIF-1和VEGF表达。运动对心肌的保护作用可能与运动上调HSF1表达,促进血管新生因子HIF-1、VEGF表达增加,促进血管新生作用有关。更多还原

【Abstract】 Objective To elucidate the effect of aerobic exercise on cardiac hypertrophy,function and angiogenesis in rats with pressure overload-induced cardiac remodeling during early stage.Methods Mice with pressure overload was induced by transverse aorta constriction(TAC).8-week-old C57 mice were divided into sedentary group(CON),exercise group(CE),TAC sedentary group(TAC),TAC + exercise group(TAE).Mice in CE and TAE groups ran on a treadmill with incremental speed and duration from 10m/min×30 minutes up to 13m/min×60 minutes 5 days per week for a total of 2 weeks.By the end of experiments,cardiac hypertrophy,contractility and angiogenesis were evaluated by echocardiography and catheterization,and vascular endothelial growth factor(VEGF),transcript levels of genes including VEGF,heat shock transcription factor-1(HSF-1),and hypoxia-inducing transcription factor-1(HIF-1) were determined by immuno-histochemical staining.Results Right carotid blood pressure increased to 50mmHg,left ventricular hypertrophy and cardiac angiogenesis appeared,and left ventricular ejection fraction(LVEF) increased in TAC sedentary group as compared to CON group.Compared to CON group,left ventricular ejection fraction(EF) increased and expressions of angiogenesis related-factors as VEGF,HSF-1 and HIF-1 up-regulated in CE group.Compared to TAC group,EF increased and expressions of VEGF and HSF-1 up-regulated in TAE group.The extent of up-regulated VEGF,HSF-1 and HIF-1 expressions in CE group was greater than that in TAE group.The change in HSF-1 expression was consistent with the changes of HIF-1 and VEGF.Conclusion Results in this study reveal that aerobic exercise has an important role on protection of developing cardiac hypertrophy,increase of LVEF and up-regulated expressions of HSF-1,HIF-1 and VEGF during the early period of pressure overload heart.更多还原