不同运动方式对小鼠骨骼肌肌萎缩相关因子表达的影响

目的:运动能够引起骨骼肌肥大,防止肌萎缩的发生.骨骼肌在萎缩状态下泛素蛋白酶通路被激活,旨在通过检测蛋白降解途径中几个关键因子mRNA的表达,探讨不同的运动形式对抗骨骼肌萎缩的效果及机制.方法:选取21只雄性老年SAMP8小鼠,随机分为对照组(C)、耐力训练组(E)、抗阻训练组(R).经过8周的训练后,检测小鼠右侧腓肠肌横截面积及MuRF-1、MAFbx、Caspase-3和IGF-1mRNA表达.结果:耐力训练和抗阻训练大鼠腓肠肌MuRF-1、MAFbx和Caspase-3 mRNA表达均显著高于对照组,但两训练组间无显著性差异;IGF-1mRNA的表达两训练组亦显著高于对照组,且抗阻训练组显著高于耐力训练组,抗阻训练组的腓肠肌纤维面积显著高于对照组和耐力训练组.结论:抗阻训练在维持肌质量方面效果优于耐力训练.两种不同的运动方式对腓肠肌质量影响之差异可能不仅仅是通过泛素蛋白酶体途径实现,还与IGF-1介导的骨骼肌再生有关.     

长期耐力训练对大鼠心肌和骨骼肌mTOR信号通路的影响

目的 探讨长期耐力训练对大鼠心肌和骨骼肌mTOR信号通路的影响.方法 雄性SD大鼠鼠随机分为长期耐力训练组(n=12)和对照组(n=12),长期耐力训练组从3月龄时开始进行4个月的耐力训练,建立长期耐力训练模型,使用western Blot蛋白印迹技术对大鼠心肌和骨骼肌mTOR信号通路中mTOR蛋白的表达进行测定;使用实时荧光定量PCR技术,对p70S6K和eIF-4E基因mRNA的表达进行测定.结果 长期耐力训练后,大鼠心脏重量和心系数与对照组相比显著增加(P<0.0S)但没有产生病理性·心肌肥大,而腓肠肌的质量与对照组相比没有明显变化;长期耐力训练后,大鼠心肌mTOR蛋白表达,p70S6K和eIF-4E mRNA的表达明显高于对照组(P<0.05),而腓肠肌mTOR蛋白表达,p70S6K和eIF-4E mRNA的表达与对照组相比无显著性变化.结论 长期耐力训练可以增强大鼠心肌mTOR信号通路的表达,产生运动性心肌肥大,改善衰老小鼠的心脏功能;长期耐力训练可通过对大鼠骨骼肌mTOR信号通路表达的影响,抑制骨骼肌的肥大.     

耐力训练对糖尿病GK大鼠有氧呼吸调节通路基因表达的影响

为探讨耐力训练对糖尿病大鼠骨骼肌有氧呼吸调节通路基因表达的影响,将12只大鼠随机分为2组:安静组(GKC,n=6只)、耐力训练组(GKE,n=6只)。GKE组跑台训练6周。末次训练后的24～48 h内切取腓肠肌,Real-time PCR检测p53、SCO2和COXII的mRNA转录,Western blot检测p53、SCO2和COXII的蛋白表达。结果发现:1)GKE组p53基因转录和蛋白表达水平与GKC组相比均显著降低;2)GKE组与GKC组相比SCO2基因转录和蛋白表达水平差异没有显著性;3)KE组COXII基因转录水平与GKC组相比差异没有显著性,但GKE组COXII蛋白表达水平非常显著低于GKC组。结果说明:耐力训练不能显著促进糖尿病大鼠线粒体有氧呼吸能力。COXII蛋白表达水平的显著下调似乎显示本实验耐力训练模型对其有氧呼吸轴有损害作用,但综合p53基因表达显著下调结果谨慎推测,这也许是受糖尿病病程影响,p53基因表达水平无法继续维持在正常稳态,其基因表达能力的下降极有可能是为了促进细胞的生存,也许是为了延缓GK大鼠病态细胞的凋亡或衰老进程。在病态条件下,细胞更重要的功能也许不是提高运动能力,而是积蓄一切力量,促使细胞生存。     

力量和耐力组合训练分子产生的干扰机制和训练学上的对策

耐力训练对骨骼肌重量的影响相对较少,而力量训练可显著诱导运动肌发生肥大。不同的训练方式诱导适应的分子机制是不同的,激活和表达各自特异的信号通路和相关的基因。力量和耐力进行组合训练时,在分子水平存在一个干扰现象,不同训练方式可诱导细胞内信号通路产生拮抗,从而抵消骨骼肌对不同运动方式产生特异性适应。当前,一些训练学上的对策已经被证明能够有效降低力量和耐力组合训练产生的干扰。对这一问题的认识有助于我们理解骨骼肌疾病的病因、老龄化时维持其新陈代谢和功能以及运动员的运动训练。     

不同强度运动训练对大鼠骨骼肌蛋白浓度OD值及Bcl-2和Bax表达的影响

目的:探讨不同强度运动训练对大鼠骨骼肌蛋白浓度OD值及Bcl-2、Bax表达的影响。方法:选用健康雄性SD大鼠60只,随机分对照组、中等强度训练组和大强度训练组。采用考马斯亮蓝法测定各组大鼠腓肠肌中蛋白浓度OD值。采用免疫印迹技术检测骨骼肌中Bcl-2和Bax蛋白含量。结果:和对照组相比,中等强度训练组大鼠腓肠肌中蛋白浓度OD值及Bcl-2的表达显著增加(P<0.05),Bax的表达无明显变化。大强度训练组大鼠腓肠肌中蛋白浓度OD值无明显变化,Bcl-2的表达显著降低(P<0.05),Bax的表达显著增加(P<0.05)。结论:中等强度的运动训练可使大鼠骨骼肌细胞中蛋白浓度OD值及Bcl-2基因蛋白增加,有效促进了骨骼肌的肥大和抑制了骨骼肌细胞凋亡的发生,而大强度运动训练可抑制骨骼肌细胞蛋白浓度OD值及Bcl-2蛋白的表达,促进Bax蛋白的表达,从而促进骨骼肌细胞的凋亡。     

耐力训练对高脂膳食大鼠骨骼肌线粒体脂肪氧化及PGC- 1α 基因表达的影响

目的:研究耐力训练对高脂膳食大鼠骨骼肌线粒体脂肪氧化相关酶活性及基因表达的影响.方法:40只SD大鼠,随机分成普通膳食对照组(c)与耐力训练组(E);高脂膳食对照组(H)与耐力训练组(R),每组10只.两耐力训练组大鼠进行8周跑台训练.结果:耐力训练使高脂膳食大鼠体重(p=0.000)、IR指数(P=0.021)显著降低并维持在正常水平,使骨骼肌线粒体β-HAD(P=0.011)、CS活性(p=0.047)、CPT-1β mRNA (P=0.037)及PGC-1α蛋白表达水平(P=0.007)显著增高.结论:耐力训练通过适度调节参与线粒体脂肪氧化关键酶β-HAD、CS活性及CPT-1β、PGC-1α基因表达,优化高脂膳食机体在线粒体水平的脂肪氧化能力.     

不同训练方式对骨骼肌P53调节线粒体有氧呼吸轴P53、SCO2和COXⅡ基因表达的影响

目的:比较耐力训练和间歇性速度训练对骨骼肌P53调节线粒体有氧呼吸轴影响能量代谢的运动适应及对P53、SCO2和CDXⅡ基因表达的影响.方法:30只大鼠随机分为3组:安静组(C,n=10)、耐力训练组(E,n=10)、间歇性速度训练组(S,n=10),训练6周.间歇性速度训练:每天9～10次10 s极量强度(≥42 m/min)的跑台运动,间歇时间30～60 s;耐力训练:每天30～60 min低强度(≤16.7 m/min)的持续跑台运动;每周均训练6天.最后一次训练结束后的24～48 h内切取腓肠肌,Real-time PCR检测P53、SCO2和COXⅡ的mRNA转录,Western blot检测P53、SCO2扣COXⅡ的蛋白表达.结果:1)E组和S组P53mRNA转录、蛋白表达水平与C组相比均没有显著性差异(P＞0.05);E组和S组相比P53mRNA转录、蛋白表达也没有显著性差异(P＞0.05);2)E组SCO2mRNA转录、蛋白表达水平均显著高于C组(P＜0.05);S组SCO2mRNA转录与C组相比没有显著性差异(P＞0.05),但S组SCO2蛋白表达水平显著高于C组(P＜0.05);E组和S组SCO2mRNA转录、蛋白表达水平均没有显著性差异(P＞0.05);3)E组COXⅡmRNA转录水平与C组相比没有显著性差异(P＞0.05),但E组ODXⅡmRNA转录水平非常显著低于S组(P＜0.01);E组COXⅡ蛋白表达水平非常显著地高于C组和S组(P＜0.01);S组COXⅡmRNA转录水平和蛋白表达水平均非常显著高于C组(P＜0.01).结论:1)P53基因转录和蛋白表达具有极强的保守性,耐力训练和间歇性速度训练都不能影响其稳态效应;2)两种训练方式对SCO2和COXⅡ基因表达在转录和转译水平上影响虽然有所不同,但都呈现出促进有氧呼吸的趋同性,间歇性速度训练可能是一种更有效的时间节省化训练方式;3)P53-SCO2-COXⅡ-有氧呼吸轴对耐力训练和间歇性速度训练产生了良好的运动性适应,在制定运动处方时,可适当结合耐力训练和间歇性速度训练来提高机体有氧呼吸能力.     

耐力训练诱导AMPKα2对鼠骨骼肌pp38和P-MEF2的影响

目的:研究耐力性跑台运动对AMPKα2 3种不同基因型鼠骨骼肌p38、pp38和P-MEF2A蛋白表达的影响,以探讨运动激活MEF2的具体机制。方法:AMPKα2 3种不同基因型鼠各20只,分别分成安静对照组和耐力训练组,每组10只。安静组小鼠不施加任何运动负荷,耐力训练组小鼠进行速度为12m/min,每天1h,每周6天,持续4周的跑台运动。Western blot法测定骨骼肌p38、pp38和核内P-MEF2A蛋白表达。结果:1)4周耐力训练后,AMPKα2 3种基因型鼠pp38蛋白表达均显著提高,并且AMPKα2转基因鼠与野生鼠相比,p38和pp38蛋白表达明显增加,而AMPKα2敲除鼠pp38表达虽然低于野生鼠,但没有显著性差异;2)耐力训练组与安静组相比,AMPKα2 3种基因型鼠骨骼肌核内P-MEF2A蛋白表达均显著增加,并且AMPKα2转基因鼠与野生鼠相比,核内P-MEF2A表达显著增加,而AMPKα2敲除鼠P-MEF2A与野生鼠相比没有显著性差异;3)42只小鼠骨骼肌内pp38与核内P-MEF2A表达量呈显著正相关(R=0.69,P<0.05)。结论:4周耐力训练对AMPKα2 3种不同基因型鼠骨骼肌内p38蛋白表达影响不大,但可以显著促进p38和MEF2A的激活。AMPKα2可能不是惟一激活p38和MEF2A的途径,耐力训练可能通过pp38激活MEF2A。     

低氧训练诱导AMPK对小鼠骨骼肌PPARα表达的影响

研究常氧耐力训练、低氧刺激以及低氧耐力训练4周后,AMPKα2转基因鼠和AMPKα2基因敲除鼠骨骼肌AMPKα1/α2磷酸化、核内PPARα蛋白含量,探讨低氧训练下AMPKα对PPARα的影响.方法:C57BL/6J野生小鼠、AMPKα2基因高表达和AMPKα2基因敲除鼠各40只,按体重随机分为4组:常氧安静对照组,常氧耐力训练组,低氧安静对照组,低氧耐力训练,每组10只.耐力训练组小鼠训练设计为:每天1小时坡度为0,速度为12 m/min的跑台训练,每周6天,持续4周.低氧方案为:每天间歇性低氧8小时,模拟海拔4500 m左右的低氧环境.测定磷酸化AMPK(Thr172)、核内PPARα蛋白含量以及PPARαmRNA含量.结果:1)四周低氧耐力训练可激活骨骼肌AMPK,促进AMPKα磷酸化;2)四周低氧耐力训练显著增加骨骼肌核内PPARα蛋白的表达;3)与WT鼠相比,低氧耐力训练显著增加OE鼠AMPKα磷酸化和核内PPARα蛋白表达,显著降低KO鼠AMPKα磷酸化和核内PPARα蛋白表达.提示核内PPARα蛋白水平与AMPK激活后的AMPKα磷酸化水平密切相关.     

运动和MicroRNAs

运动通过增加机械负荷或代谢应激可诱导不同的适应,从而调节生理系统的功能,如骨骼肌、心血管和神经系统.MicroRNAs（miRNA）是非编码、小分子mRNA,作为基因转录后的阻遏物.MicroRNAs通过直接阻遏或降解mRNA,沉默mRNA转录,最终影响蛋白的丰度.实验研究业已发现耐力和力量练习,骨骼肌特异miRNA的表达变化.在运动方面研究MicroRNAs分子行为可助于认识运动治疗的作用.     

阻力训练及超等长阻力训练对下肢肌肉活性和力量的影响

目的:观察阻力训练和超等长阻力训练后下肢肌肉力量变化,比较肌肉激活模式的不同.方法:将16名男性篮球运动员随机分成两组,分别实施8周下肢阻力训练和超等长阻力训练.采用3-D测力台测试训练前、后最大随意收缩值,用表面肌电记录训练前、后6次重复训练动作的胫骨前肌、腓肠肌外侧头、股直肌、股外侧肌、股二头肌的激活信号,计算积分肌电值和髋、膝、踝关节周围拮抗肌共激活.结果:两组下肢肌肉力量均显著提高,阻力训练组效果较明显.超等长阻力训练组肌肉活性显著高于阻力训练组.训练后超等长阻力训练组肌肉活性出现适应性变化,髋、踝关节拮抗肌共激活显著升高,膝关节拮抗肌共激活训练前、后没有显著性差异.阻力训练组训练前、后肌肉活性及拮抗肌共激活没有显著变化.结论:超等长阻力训练有助于提高肌肉间协调性,可以优化肌肉动作的运动策略.     

不同运动方式对衰老小鼠心肌细胞凋亡的影响

目的:探讨不同运动方式对衰老小鼠心肌细胞凋亡的影响.方法:雄性3月龄SAMP8小鼠随机分为年轻对照组(n=12)、衰老对照组(n=12)、长期有氧运动组(n=12)和抗阻训练组(n=12).长期有氧运动组和抗阻训练组从3月龄开始进行3个月的运动训练,在6月龄达到衰老时处死、取材.使用实时荧光定量PCR技术,对各组小鼠心肌Bcl-2和Bax基因mRNA的表达进行测定.结果:长期有氧运动和抗阻训练后,小鼠心脏重量和心系数与衰老对照组相比显著增加(p<0.05)但没有产生病理性心肌肥大;衰老对照组和长期有氧运动组心肌Bcl-2基因mRNA的表达与年轻对照组和抗阻训练组相比显著下降(P<0.05),Bax基因mRNA的表达则显著上升(P＜0.05).结论:长期有氧运动和抗阻训练町以导致运动性心肌肥大;长期有氧运动后可加剧衰老心肌细胞凋亡的产生;抗阻训练可以减少衰老心肌细胞凋亡.     

游泳运动锻炼对Ⅱ型糖尿病大鼠血清和骨骼肌musclin含量的影响

目的研究Ⅱ型糖尿病大鼠血清和骨骼肌musclin含量的变化,并探讨运动训练对Ⅱ型糖尿病大鼠血清和骨骼肌musclin含量的影响。方法 SD大鼠随机分为正常对照组(C,n=8)、糖尿病对照组(DM,n=9)和糖尿病运动锻炼组(DME,n=10)。检测大鼠空腹血糖和血清、腓肠肌musclin含量。结果与C组相比,DM组大鼠血清胰岛素含量和胰岛素敏感性明显降低,空腹血糖水平显著增加;且血清和腓肠肌musclin含量显著升高;与DM组相比,DME组大鼠血清胰岛素和胰岛素敏感性显著升高,空腹血糖水平显著降低;且血清和腓肠肌musclin含量显著降低。结论 Musclin在Ⅱ型糖尿病过程中可能起着非常重要的作用;长期的有氧运动锻炼可能通过降低Ⅱ型糖尿病大鼠血清和腓肠肌musclin的含量,增加骨骼肌从血液中摄取葡萄糖的能力,从而降低血糖。     

自变频气动加载振动力量耐力训练对男子游泳运动员力量水平的影响

运用获专利的新型自变频气动加载振动力量训练器,对12名1级男子游泳运动员进行了8周的振动和气动加载动态力量耐力训练,通过与训练方式相同的测量获得了实验前后动作最大速度、最大动态力(1RM)、最大力量功率、动态力量耐力(nRM)和最大等长力量以及上臂围度指标。结果表明:振动与传统力量(气动加载)训练方法均可提高动态力量耐力,效果相当;相比传统的力量训练,振动力量训练的优势在于发展最大动态力量、快速力量和动作速度。     

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(?max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(?max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as improving sprinting ability at the end of a race.     

Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners

Abstract

The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([Vdot]O_2max), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [Vdot]O_2max (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups < 0.08). All three modes of strength training used concurrently with endurance training were effective in improving treadmill running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as improving sprinting ability at the end of a race.     

Part I: Biomechanics

The purpose of this study was to determine whether the sequence of strength training before endurance training (ST/ET) is more or less effective than endurance training followed by strength training (ET/ST). Twenty‐three females and 11 males were assigned to one of three groups: ST/ET (n= 15), ET/ST (n= 15) or control (n = 4). The 7‐week training programme consisted of strength training using 10 exercises for two sets of 3–12 repetitions and running for 20–25 min at 60–90% of heart rate reserve. Maximal oxygen uptake (VO₂ max) was measured during a graded treadmill test, and muscular strength was assessed using one‐repetition maximum tests for the bench press (BP), shoulder press (SP), arm curl (AC) and leg press (LP). The VO₂ max significantly (P < 0.05) increased 6.7 and 6.2% for the ST/ET and ET/ST groups, respectively. There was no significant (P > 0.05) difference between the two experimental groups. Muscular strength significantly (P <0.05) improved by 15.2% (BP), 16.6% (SP), 17.2% (AC) and 11.9% (LP) for the ST/ET group and 19.9% (BP), 24.1% (SP), 20.9% (AC) and 14.0% (LP) for the ET/ST group. There were no significant (P > 0.05) differences between the two experimental groups for the BP, AC and LP; however, the ET/ST group increased (P < 0.05) SP strength more than the ST/ET group. In conclusion, adaptations to a combination of short‐term endurance and strength training as assessed by VO₂ max and BP, AC and LP strength appear to be independent of whether endurance training occurs prior to or following strength training.     

SOCS-3在耐力运动改善膳食性瘦素抵抗中作用机制的研究

目的:分析SOCS-3与瘦素受体LRb的结合作用,探讨高脂膳食条件下耐力运动对骨骼肌瘦素抵抗的预防或改善机制.方法:32只大鼠随机平均分成普通膳食对照组(CS)、普通膳食运动组(CE)、高脂膳食对照组(HS)、高脂膳食运动组(HE).CE、HE组进行12周跑台训练,跑速20 m/min.最后一次训练后48 h,测试空腹血糖、血液甘油三酯(TG)、胰岛素、瘦素以及红色(RG)、白色(WG)腓肠肌的甘油三酯.采用Real-time PCR测定RG、WG肌的SOCS-3mRNA表达水平,采用免疫共沉淀技术测定RG、WG肌SOCS-3蛋白与瘦素受体LRb的结合活性.结果:1)HS组体重增长率最高,HS组体重、血糖、血液甘油三酯、胰岛素、瘦素均显著高于CS组(P＜0.05);HE组血液胰岛素、瘦素水平显著低于HS组(P＜0.05).2)RG肌TG含量:HS组显著低于CS组(P＜0.05),HE组显著高于HS组(P＜0.05).WG肌TG含量:CE组显著高于CS组(P＜0.05),既组显著高于HS组(P＜0.05).3)RG肌SOC-3mRNA表达:CE、HS组显著高于CS组(P＜0.01).WG肌SOCS-3mRNA表达:CE组显著高于CS组(P＜0.01).4)RG肌SOCS-3蛋白与瘦素受体LRb的结合活性:HS组显著高于CS组(P＜0.05),HE显著低于HS组(P＜0.05).结论:1)高脂膳食显著降低红色腓肠肌的TG含量,表明高脂膳食性瘦素抵抗易发于红肌,高脂膳食能降低红肌的脂肪代谢能力;耐力运动对红肌的瘦素抵抗有显著的逆转作用;2)耐力运动和高脂膳食都能上调红色腓肠肌SOCS-3 mRNA表达,SOCS-3 mRNA表达对运动和膳食的应答反应在肌纤维类型之间存在差异,至少白肌耐力运动与高脂膳食还存在负交互作用;3)高脂膳食导致骨骼肌瘦素抵抗,至少有一部分机制使SOCS-3与LRb受体的结合增加.耐力运动对高脂膳食性瘦素抵抗的改善机制,至少有一部分是因为运动解除了SOCS-3与LRb受体的结合,减弱了SICS-3对瘦素信号的抑制作用.