Maintenance of contractile force and increased fatigue resistance in slow-twitch skeletal muscle of mice fed a high-fat diet
Maintenance of contractile force and increased fatigue resistance in slow-twitch skeletal muscle of mice fed a high-fat diet
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DOI：
10.1152/japplphysiol.00218.2020
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发表时间：
2021-03-01
影响因子：
3.3
通讯作者：
Watada, Hirotaka
中科院分区：
文献类型：
--
作者：
Eshima, Hiroaki;Tamura, Yoshifumi;Watada, Hirotaka
高脂肪饮食（HFD）的消费显着增加跑步机运行期间的运动耐力表现。然而，HFD的消耗是否通过增强肌肉抗疲劳性来增加耐力还没有得到澄清。在这项研究中，我们研究了HFDs对慢收缩优势肌的收缩力和抗疲劳性的影响。分析了喂食HFD（60%kcal来自脂肪）或低脂饮食（LFD）12周的雄性C57 BL/6 J小鼠的比目鱼肌（SOL）。在静息条件下和重复强直收缩（100 Hz，50次收缩和2 s间隔）诱导的疲劳期间测量肌肉收缩力。HFD组和LFD组之间肌肉抽搐或强直力的差异不明显，而HFD组的抗疲劳性更高。HFD喂养小鼠的SOL肌肉显示与氧化能力相关的标记物水平增加，如琥珀酸脱氢酶（SDH）和柠檬酸合酶（CS）活性。此外，电子显微镜分析表明，线粒体和线粒体的总数！HFD组SOL肌肉的体积密度增加。这些发现表明，HFD消耗诱导增加的肌肉疲劳阻力在慢收缩优势肌纤维。HFD的这种效果可能与氧化酶活性升高，线粒体含量高，或两者兼而有之。新&值得注意的是在这项研究中，我们研究了HFD对肌肉收缩力和抗疲劳性的影响慢收缩优势肌肉离体。我们发现HFD组和LFD组的收缩功能相当，而HFD组的抗疲劳性更高。HFD的这种作用可能与氧化酶活性升高、线粒体含量高或两者兼而有之有关。
Consumption of a high-fat diet (HFD) significantly increases exercise endurance performance during treadmill running. However, whether HFD consumption increases endurance capacity via enhanced muscle fatigue resistance has not been clarified. In this study, we investigated the effects of HFDs on contractile force and fatigue resistance of slow-twitch dominant muscles. The soleus (SOL) muscle of male C57BL/6J mice fed an HFD (60% kcal from fat) or a low-fat diet (LFD) for 12 wk was analyzed. Muscle contractile force was measured under resting conditions and during fatigue induced by repeated tetanic contractions (100 Hz, 50 contractions, and 2-s intervals). Differences in muscle twitch or tetanic force were not evident between HFD and LFD groups, whereas fatigue resistance was higher in the HFD groups. The SOL muscle of HFD-fed mice showed increased levels of markers related to oxidative capacity such as succinate dehydrogenase (SDH) and citrate synthase (CS) activity. In addition, electron microscopy analyses indicated that the total number of mitochondria and mitochondria! volume density increased in the SOL muscle of the HFD groups. These findings suggest that HFD consumption induces increased muscle fatigue resistance in slow-twitch dominant muscle fibers. This effect of HFD may be related to elevated oxidative enzyme activity, high mitochondrial content, or both.NEW & NOTEWORTHY In this study, we examined the effects of HFDs on muscle contractile force and fatigue resistance of slow-twitch dominant muscles ex vivo. We found that contractile function was comparable between the HFD groups and the LFD group, whereas fatigue resistance was higher in the HFD groups. This effect of HFD may be related to elevated oxidative enzyme activity, high mitochondrial content, or both.