β-Carotene Increases Muscle Mass and Hypertrophy in the Soleus Muscle in Mice
β-Carotene Increases Muscle Mass and Hypertrophy in the Soleus Muscle in Mice
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DOI：
10.3177/jnsv.61.481
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发表时间：
2015-12-01
影响因子：
1.6
通讯作者：
Yamaji, Ryoichi
中科院分区：
文献类型：
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作者：
Kitakaze, Tomoya;Harada, Naoki;Yamaji, Ryoichi
预计有效维持或增强骨骼肌质量的补充剂和天然存在的营养品有助于预防活动性降低和发生代谢疾病的风险增加。然而，关于现有食物成分的信息仍然普遍缺乏。在本研究中，我们研究了在生理条件下，膳食β-胡萝卜素对骨骼肌数量和质量的影响。雄性ddY小鼠（8周龄）口服β-胡萝卜素（0.5mg，每日一次）14天。膳食β-胡萝卜素对体重没有影响，但增加比目鱼肌/体重比。比目鱼肌肌纤维的横截面积（CSA）增加，表明β-胡萝卜素的施用诱导肌肉肥大。在施用β-胡萝卜素的小鼠的比目鱼肌中，抽搐力倾向于增加（p=0.06）并且强直力显著增加，而比力（每个CSA的力）保持不变。饲料β-胡萝卜素可增加胰岛素样生长因子1（IGF-1）剪接体Igf-1 ea的mRNA水平，但对肝脏mRNA水平和血清IGF-1水平无影响。β-胡萝卜素促进比目鱼肌中的蛋白质合成并降低泛素结合物的水平，但对两种atrogenes Atrogin-1和Murf 1的mRNA水平没有影响。另一方面，β-胡萝卜素对自噬标记蛋白轻链3的加工没有影响。这些结果表明，在小鼠中，β-胡萝卜素的管理增加质量和诱导比目鱼肌功能性肥大，可能是通过促进IGF-1介导的蛋白质合成和通过减少泛素介导的蛋白质降解。
Supplements and naturally occurring nutraceuticals effective for maintenance or enhancement of skeletal muscle mass are expected to contribute to prevention of decreased mobility and increased risk of developing metabolic diseases. However, information about available food components remains widely unavailable. In the present study, we investigated the effects of dietary beta-carotene on the quantity and quality of skeletal muscle under physiological conditions. Male ddY mice (8 wk old) were orally administered beta-carotene (0.5 mg once daily) for 14 d. Dietary beta-carotene had no influence on body weight, but increased the soleus muscle/body weight ratio. The cross-sectional area (CSA) in muscle fibers of the soleus muscle was increased, indicating that administration of beta-carotene induces muscle hypertrophy. In the soleus muscle of the beta-carotene-administered mice, twitch force tended to be increased (p=0.06) and tetanic force was significantly increased, whereas specific force (force per CSA) remained unchanged. Dietary beta-carotene increased the mRNA level of insulin-like growth factor 1 (Igf-1) as its splicing variant Igf-1ea, but had no influence on the liver mRNA level or serum IGF-1 level. beta-Carotene promoted protein synthesis in the soleus muscle and reduced levels of ubiquitin conjugates, but had no influence on the mRNA levels of two atrogenes, Atrogin-1 and Murf1. On the other hand, beta-carotene had no influence on the processing of the autophagy marker protein light chain 3. These results indicate that in mice, administration of beta-carotene increases mass and induces functional hypertrophy in the soleus muscle, perhaps by promoting IGF-1-mediated protein synthesis and by reducing ubiquitin-mediated protein degradation.