运动预适应干预压力超负荷心肌重构模型小鼠的心肌功能及细胞凋亡  

Effects of exercise preconditioning on myocardial protection and apoptosis in a mouse model of myocardial remodeling due to early stress overload

作　　者：邓爽 蒲锐 陈子扬 张建超 袁凌燕[2] Deng Shuang;Pu Rui;Chen Ziyang;Zhang Jianchao;Yuan Lingyan(School of Health,Tianhua College,Shanghai Normal University,Shanghai 201815,China;School of Physical Education,Shanghai Normal University,Shanghai 200234,China)

机构地区：[1]上海师范大学天华学院健康学院,上海市201815 [2]上海师范大学体育学院,上海市200234

出　　处：《中国组织工程研究》2022年第5期717-723,共7页Chinese Journal of Tissue Engineering Research

基　　金：国家自然科学基金项目(31371196),项目负责人:袁凌燕。

摘　　要：背景:研究已表明长期规律有氧运动不仅能降低血压,还具有改善高血压病理性心肌肥厚、心肌纤维化致心室重构的作用。目的:探讨游泳运动预处理对压力超负荷代偿期小鼠心肌凋亡与心肌重构的影响。方法:选取六七周龄雄性C57B/L6小鼠随机分为对照组、运动组、手术组、手术运动组。运动组和手术运动组小鼠进行4周的游泳运动(90 min/次,2次/d,7 d/周);在完成游泳运动后,手术组和手术运动组2组小鼠进行主动脉缩窄手术建立压力超负荷心肌重构模型,采用27G针头结扎,使主动脉缩窄70%以上;对照组小鼠进行假手术只穿线不结扎。2周后进行心脏超声检测并取材,观察心肌细胞的凋亡情况。采用Western Blot方法检测小鼠心肌组织中热休克蛋白70、P53蛋白的表达水平;RT-PCR方法检测小鼠P53、Bcl-2、Bax基因的表达水平。结果与结论:(1)主动脉缩窄手术后2周小鼠心脏处于代偿期,与对照组相比,手术组的心重指数,左室短轴缩窄率均明显升高(P <0.01),心室壁厚度与心肌纤维化显著增加(P <0.01),心功能无显著下降;手术运动组心室壁厚度明显小于手术组(P <0.05),心肌纤维化水平与凋亡细胞计数显著降低(P <0.01);(2)与对照组相比,手术组P53蛋白表达量显著增加(P <0.01),热休克蛋白70蛋白表达量显著下降(P <0.01);与手术组相比,手术运动组P53蛋白表达量下降(P<0.05),热休克蛋白70蛋白表达量升高(P<0.05);(3)与对照组相比,手术组Bax mRNA和P53 mRNA表达增多(P <0.01),而Bcl-2 mRNA表达量和Bcl-2/Bax值下降(P <0.01);与手术组相比,手术运动组Bax mRNA表达水平下降(P <0.05),P53 mRNA表达水平下降(P <0.01),Bcl-2 mRNA表达水平和Bcl-2/Bax比值明显升高(P <0.01);(4)结果提示,小鼠心脏在2周的主动脉缩窄手术后处于病理性心肌肥厚的代偿期,4周的运动预适应可增强压力超负荷早期小鼠的心功能,维持并延缓早期心肌代偿重构发生BACKGROUND: Studies have shown that long-term regular aerobic exercises can lower blood pressure and improve ventricular remodeling caused by hypertensive myocardial hypertrophy and myocardial fibrosis.OBJECTIVE: To investigate the effects of swimming exercise preconditioning on myocardial apoptosis and remodeling in mice during pressure overload compensatory period.METHODS: Male C57 B/L6 mice aged 6-7 weeks were randomly divided into control group, exercise group, operation group and operation+exercise group. Mice in the exercise and operation+exercise groups were subjected to 4-week swimming exercises(90 minutes per session, twice per day, and 7 days per week). Transverse aorta constriction was then used to construct a model of myocardial remodeling in the operation and operation+exercise groups. The aorta was ligated with a 27 G needle to make the aorta constricted by more than 70%. Two weeks later, cardiac ultrasonography was performed and myocardial samples were collected to observe the apoptosis of myocardial cells. The expression levels of heat shock protein 70 and P53 proteins in mouse myocardial tissue were detected by western blot. The expression levels of P53, Bcl-2 and Bax in mice were detected by RT-PCR.RESULTS AND CONCLUSION: The heart was in the compensatory stage at 2 weeks after TAC surgery. Compared with the control group, the heart weight index and left ventricular shorting rate were significantly increased in the operation group(P < 0.01), the ventricular wall thickness and myocardial fibrosis were significantly increased(P < 0.01), but the heart function was not significantly decreased. Compared with the operation group, the ventricular wall thickness was significantly lower in the operation+exercise group(P < 0.05), and the level of myocardial fibrosis and apoptosis cell count were significantly decreased(P < 0.01). Western blot results showed that compared with the control group, the protein expression of P53 in the operation group was significantly increased(P < 0.01), and the protein expr

关 键 词：运动预适应 高血压 心肌重构 热休克蛋白 细胞凋亡 

分 类 号：R459.9[医药卫生—治疗学] R714[医药卫生—临床医学]