同期有氧与抗阻训练对老年小鼠快缩型骨骼肌蛋白质合成的影响  

The Effect of Concurrent Aerobic and Resistance Exercise Training on Protein Synthesis of Fast-Twitch Skeletal Muscle in Old Mice

作　　者：王世香[1] 赵艳[2] 尚画雨 王前进 丁孝民[1] 刘绍生[1] 夏志 Wang Shixiang;Zhao Yan;Shang Huayu;Wang Qianjin;Ding Xiaomin;Liu Shaosheng;Xia Zhi(College of Physical Education,Jinggangshan University,Ji'an 343009,China;College of Physical Education and Health,Wenzhou University,Wenzhou 325035,China;School of Sports Medicine and Health,Chengdu Sport Institute,Chengdu 610041,China;College of Physical Education and Science,Wenzhou Medical University,Wenzhou 325035,China)

机构地区：[1]井冈山大学体育学院,吉安343009 [2]温州大学体育与健康学院,温州325035 [3]成都体育学院运动医学与健康学院,成都610041 [4]温州医科大学体育科学学院,温州325035

出　　处：《中国运动医学杂志》2023年第9期712-722,共11页Chinese Journal of Sports Medicine

基　　金：国家自然科学基金项目(31960192);江西省杰出青年基金项目(20202ACBL216004);浙江省自然科学基金项目(LY23C110001);四川省自然科学基金项目(2023NSFSC1524);温州市基础性科研项目(Y20220209)。

摘　　要：目的:观察同期有氧与抗阻训练对老年小鼠快缩型骨骼肌蛋白质合成的影响并探讨其潜在机制。方法:16月龄C57BL/6小鼠根据体重随机纳入衰老对照与运动干预组,3月龄同品系小鼠作为青年对照组,每组8只。运动干预组每周一、三、五以自体重3%负荷进行45分钟耐力训练,每周二、四、六以自体重40%~50%负荷进行力量训练,共计8周。末次训练24小时后处死全部小鼠取样。采用苏木精伊红染色切片观察肌纤维横截面积与直径;Bradford法进行蛋白定量;嘌呤霉素表面标记翻译法检测蛋白质合成率;网屏悬吊时间评价协调性;后肢抓握力评价肌肉力量;力竭游泳时间评价运动耐力;免疫印迹法检测哺乳动物雷帕霉素靶蛋白(mTORSer2448)、p70核糖体蛋白S6激酶(p70S6K^(Thr389))、真核翻译起始因子4E结合蛋白1(4E-BP1^(Thr37/46))磷酸化表达及Ⅱb型肌球蛋白重链(MHCⅡb)的蛋白表达。结果:衰老对照组与运动干预组小鼠骨骼肌纤维横截面积、直径、蛋白质含量、蛋白质合成率、蛋白质合成调控相关蛋白表达、肌肉力量与运动耐力均显著低于青年对照组。运动干预组蛋白质含量、蛋白质合成率、骨骼肌横截面积与直径、网屏悬吊时间、抓握肌力及力竭游泳能力均显著高于衰老对照组,mTORSer2448、p70S6K^(Thr389)、4E-BP1^(Thr37/46)磷酸化表达与MHCⅡb蛋白表达较衰老对照组亦显著上调。结论:同期运动训练可以促进老年小鼠快缩型骨骼肌蛋白质合成和肌肉肥大,增强其肌肉力量与运动耐力,具有改善衰老性骨骼肌萎缩的潜力,其机制可能涉及快缩型骨骼肌内mTOR/p70S6K/4E-BP1信号通路的活化。Objective To observe the effect of combined aerobic and resistance exercise training on protein synthesis of fast-twitch skeletal muscle in aging mice,and explore its mechanism.Methods Sixteen-month-old C57BL/6 mice were randomly divided into an aging control group and a combined exercise traininggroup,each of eight,according to their body weight,while another eight three-month-old mice were allocated into the youth control group.The combined exercise training group underwent 45-minute swimming on Monday,Wednesday and Friday,and incremental jumping submersed in water with overload corresponding to 40%-50%body weight on Tuesday,Thursday and Saturday for 8 weeks.Twenty-four hours after the training,all mice were sacrificed.The cross-sectional area(CSA)and diameter of muscle fibers were observed by using the hematoxylin-eosin staining.The protein content was determined with Bradford protein assay,while the protein synthesis rate was detected using the surface sensing of translation.Moreover,the body coordination,muscle strength and exercise tolerance were assessed using the hanging grid duration,maximal grip strength of hind limbs and exhaustive swimming,respectively.Meanwhile,the phosphorylation rate of mammalian target of rapamycin(mTOR)s24s,p70 ribosomal protein S6 kinase(p70S6K)^(Thr389),and Eukaryotic translation initiation factor 4E binding protein 1(4E-BP1)^(Thr37/46) as well as the protein expression of myosin heavy chain IIb(MHC Ib)were detected using Western blotting.Results The fiber CSA and diameter,protein content,protein synthesis rate,protein synthesis regulation related protein expression,muscle strength and exercise endurance of the aging groups were significantly lower than the youth control group.Moreover,the protein content,protein synthesis rate,CSA and diameter of skeletal muscle,hanging grid duration,maximal grip strength and exhaustive swimming time of the exercise intervention group were significantly higher than the aging control group.In addition,the expression of MHC Ib as well as the pho

关 键 词：同期训练 衰老性骨骼肌萎缩 骨骼肌 蛋白质沉积 蛋白质合成 

分 类 号：R685[医药卫生—骨科学]