低强度运动改善急性心肌梗死后大鼠运动能力与骨骼肌自噬机制  

Low-intensity exercise improves aerobic exercise capacity in rats after acute myocardial infarction and the possible role of skeletal muscle autophagy

作　　者：陈丽妹 彭雯雯 许桂清 郭玥 魏菱洁 林诚[3] 潘燕霞[3] 王诗忠 CHEN Li-mei;PENG Wen-wen;XU Gui-qing;GUO Yue;WEI Ling-jie;LIN Cheng;PAN Yan-xia;WANG Shi-zhong(Department of Physical Education and Research,Fujian Medical University,Fuzhou Fujian 350004,China)

机构地区：[1]福建医科大学体育教研部,福建福州350004 [2]厦门医学院临床医学系 [3]福建医科大学健康学院康复医学系 [4]福建医科大学

出　　处：《中华高血压杂志》2020年第7期661-666,共6页Chinese Journal of Hypertension

基　　金：国家自然科学基金(81372111);福建省自然科学基金(2014J01339)。

摘　　要：目的观察低强度运动对急性心肌梗死(简称心肌梗死)后大鼠有氧运动能力和骨骼肌自噬水平的影响,探讨运动改善有氧运动能力的机制。方法30只雄性SD大鼠,体质量180~200 g,随机分为假手术组、心肌梗死组和心肌梗死运动组。结扎左冠状动脉前降支制备心肌梗死模型。术后3 d心肌梗死运动组在跑台上进行适应性运动,术后1周进行低强度跑台运动,跑台速度从10~15递增至15~20 m/min,运动时间从10~30递增至30~60 min/d,5 d/周,共4周。运动结束检测大鼠最大运动距离和运动时间、心脏质量、心脏质量指数和心肌梗死面积。透射电镜观察腓肠肌自噬体或自噬溶酶体形态。Western blot检测腓肠肌自噬相关蛋白Beclin-1和微管相关蛋白1轻链3(LC3)-Ⅰ、Ⅱ表达。结果心肌梗死组和心肌梗死运动组心肌梗死面积分别为左心室面积的(30.8±5.5)%和(27.6±5.0)%。心肌梗死组心脏质量和心脏质量指数高于假手术组[(1097.0±97.4)比(740.8±68.7)mg,(3.0±0.4)比(2.1±0.2)mg/g,均P<0.01];心肌梗死运动组心脏质量[(854.4±65.3)mg]和心脏质量指数[(2.5±0.2)mg/g]低于心肌梗死组(均P<0.01)。心肌梗死组最大运动距离和运动时间低于假手术组[(391.9±55.7)比(535.4±24.3)m,(20.6±2.1)比(26.4±0.8)min,均P<0.01];心肌梗死运动组最大运动距离[(478.3±53.5)m]和运动时间[(23.7±1.5)min]高于心肌梗死组(均P<0.05)。电镜下假手术组腓肠肌细胞内偶见自噬溶酶体,心肌梗死组自噬溶酶体散在分布,心肌梗死运动组自噬溶酶体簇状分布。心肌梗死组Beclin-1蛋白表达和LC3-Ⅱ/LC3-Ⅰ轻度升高,但与假手术组相比,差异无统计学意义。心肌梗死运动组Beclin-1蛋白表达和LC3-Ⅱ/LC3-Ⅰ高于心肌梗死组(P<0.05)和假手术组(P<0.01)。结论低强度运动改善急性心肌梗死大鼠有氧运动能力,其机制可能与增强骨骼肌自噬水平有关。Objective To investigate the effects of low intensity exercise on aerobic exercise capacity and autophagy of skeletal muscle in rats after acute myocardial infarction and its possible mechanisms.Methods Thirty male Sprague Dawley rats,weighting 180-200 g,were randomly divided into 3 groups:sham group(Sham),myocardial infarction group(MI)and MI with exercise training group(MI+ExT).The MI model was established by ligation of the left anterior descending artery of rats.Three days after surgery,rats of the MI+ExT group run on a treadmill for adaptation.One week after surgery,exercise training was carried out in the low intensity for 4 weeks.The treadmill speed was increased from 10-15 to 15-20 m/min,and exercise duration was increased from 10-30 to 30-60 min/d,5 days weekly for 4 weeks.At the end of exercise training,the maximum exercise distance,exercise time,heart weight(HW)and heart weight index(HWI)and infarct size were determined.The morphology of autophgosome or autolysosome of gastrocnemius was observed by transmission electron microscopy.The protein expressions of Beclin-1 and microtubule-associated protein 1 light chain 3(LC3)-Ⅰ/Ⅱof gastrocneus were measured by Western blot.Results Compared with the sham group,the infarction area of MI group and MI+ExT group was(30.8±5.5)%and(27.6±5.0)%of left ventricle,respectively.HW and HWI in the MI group were significantly higher than those in the sham group[(1097.0±97.4)vs(740.8±68.7)mg,(3.0±0.4)vs(2.1±0.2)mg/g,P<0.01].However,HW[(854.4±65.3)mg]and HWI[(2.5±0.2)mg/g]in MI+ExT group were significantly lower than those in the MI group(P<0.01).The maximal exercise distance and duration in the MI group were obviously lower than those in the sham group[(391.9±55.7)vs(535.4±24.3)m,(20.6±2.1)vs(26.4±0.8)min,both P<0.01],but significantly higher than those in the MI+ExT group[exercise distance(478.3±53.5)m,duration(23.7±1.5)min,both P<0.05].Autophgosome of the gastrocneus was seldom found in the sham group,while scattered in the MI group and clustered in the

关 键 词：运动训练 心肌梗死 运动能力 自噬 

分 类 号：R542.22[医药卫生—心血管疾病]