Lee Sang-Rok, Khamoui Andy V, Jo Edward, Zourdos Michael C, Panton Lynn B, Ormsbee Michael J, Kim Jeong-Su
Department of Kinesiology and Dance, New Mexico State University, Las Cruces, NM, USA.
Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL, USA.
Exp Physiol. 2017 Nov 1;102(11):1500-1512. doi: 10.1113/EP086317. Epub 2017 Sep 30.
What is the central question of this study? This study examined the effects of 20 weeks of administration of conjugated linoleic acids/omega-3 fatty acids with or without programed resistance exercise training on body composition, skeletal muscle properties and functional capacity in middle-aged mice fed a high-fat diet. What is the main finding and its importance? Chronic daily administration of conjugated linoleic acids/omega-3 fatty acids with resistance exercise training can help to blunt fat gain, alleviate loss of myogenic capacity and sensorimotor function and lower tissue inflammation in middle-aged mice during chronic high-fat diet-induced catabolism. This study investigated the effects of 20 weeks of combined conjugated linoleic acid (CLA)/omega-3 fatty acid (n-3) administration independently or combined with resistance exercise training (RET) on skeletal muscle in middle-aged mice consuming a high-fat diet (HFD). Nine-month-old C57BL/6 mice were randomly assigned into four experimental groups (H, high-fat diet; HE, H + RET; HCN, H + CLA/n-3; and HECN, H + CLA/n3 + RET). Body composition and functional capacity were assessed pre- and post-intervention. Muscle tissues were collected at 14 months of age. ANOVA was used, with significance set at P ≤ 0.05. Fat mass significantly increased in H (+74%), HE (+142%) and HECN (+43%) but not in HCN. Muscle wet weights were significantly lower in H and HCN than in HE and HECN. Grip strength substantially declined in H (-15%) and HCN (-17%), whereas sensorimotor function significantly declined only in H (-11%). HECN exhibited improvement in strength (+22%) and sensorimotor coordination (+17%). In comparison to H, muscle tumour necrosis factor-α mRNA expression was significantly lower in HE (-39%), HCN (-24%) and HECN (-21%), respectively. Mean myofibre cross-sectional areas were markedly lower in H and HCN than in HE and HECN. H showed significantly lower satellite cell abundance and numbers of myonuclei than all other groups. Our findings suggest that long-term daily CLA/n-3 intake with resistance training improved sensorimotor function, ameliorated fat gain and prevented loss of myogenic capacity while lowering tumour necrosis factor-α expression during chronic HFD.
本研究的核心问题是什么？本研究考察了在高脂饮食喂养的中年小鼠中，连续20周给予共轭亚油酸/ω-3脂肪酸，以及是否联合程序性抗阻运动训练，对身体组成、骨骼肌特性和功能能力的影响。主要发现及其重要性是什么？在慢性高脂饮食诱导的分解代谢过程中，每日长期给予共轭亚油酸/ω-3脂肪酸并结合抗阻运动训练，有助于抑制中年小鼠的脂肪增加，减轻生肌能力和感觉运动功能的丧失，并降低组织炎症。本研究调查了连续20周单独给予共轭亚油酸（CLA）/ω-3脂肪酸（n-3）或联合抗阻运动训练（RET），对高脂饮食（HFD）喂养的中年小鼠骨骼肌的影响。将9月龄的C57BL/6小鼠随机分为四个实验组（H，高脂饮食组；HE，高脂饮食+抗阻运动训练组；HCN，高脂饮食+CLA/n-3组；HECN，高脂饮食+CLA/n3+抗阻运动训练组）。在干预前后评估身体组成和功能能力。在14月龄时收集肌肉组织。采用方差分析，显著性设定为P≤0.05。H组（增加74%）、HE组（增加142%）和HECN组（增加43%）的脂肪量显著增加，但HCN组未增加。H组和HCN组的肌肉湿重显著低于HE组和HECN组。H组（降低15%）和HCN组（降低17%）的握力大幅下降，而仅H组的感觉运动功能显著下降（降低11%）。HECN组的力量（增加22%）和感觉运动协调性（增加17%）有所改善。与H组相比，HE组（降低39%）、HCN组（降低24%）和HECN组（降低21%）的肌肉肿瘤坏死因子-α mRNA表达分别显著降低。H组和HCN组的平均肌纤维横截面积明显低于HE组和HECN组。H组的卫星细胞丰度和肌核数量显著低于所有其他组。我们的研究结果表明，在慢性高脂饮食期间，长期每日摄入CLA/n-3并进行抗阻训练可改善感觉运动功能，减轻脂肪增加，防止生肌能力丧失，同时降低肿瘤坏死因子-α的表达。
