Mechanisms of exercise-induced muscular hypertrophy : A study with venous-occlusion models.

运动引起的肌肉肥大的机制：静脉闭塞模型的研究。

• 批准号: 16300207
• 负责人: ISHII Naokata
• 金额: $ 9.66万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16300207/
• 关键词: Resistance training; Muscle hypertrophy; Vascular occlusion; Exercise intensity; Muscle oxygenation; DNA microarray; Growth factors; Muscle satellite cells; 運動・トレーニング; myostatin; follistatin; caveolin; 遺伝子発現; 熱ショックタンパク質

We have previously shown that low-intensity resistance training cause increases in muscular size and strength when combined with moderate vascular occlusion. Elucidating its mechanism likely contributes not only to understand the common mechanisms of exercise-induced muscular hypertrophy but also to develop new exercise methods with much reduced mechanical stress. For this purpose, we developed two types of exercise model (animal and human models). In the animal model, major veins from hindlimb muscles of the rats were surgically crush-occluded with a heated metal needle. The chronic restriction of venous blood flow for 2 weeks caused in hindlimb muscles increases in wet and dry weights and total protein content, except for the soleus muscle. In the plantaris muscle, muscle fibers of all types (types I, IIa and IIb/x) showed an increase in their cross-sectional area (CSA). In addition, transitions of muscle-fiber types directed towards faster subtypes were observed to occur. The concen … More trations of glycogen, lactate, nitric oxide (NO), HSP-72 and active form of hepatocyte growth factor (HGF) increased, whereas that of myostatin decreased. Expressions of NOS-1 increased, whereas that of IGF-I tended to increase without significance. In the human model, low-intensity resistance exercise for knee extensor muscles (30% of one-repetition maximum) was performed twice daily for 2 weeks. Even with such short period of training, increases in muscle cross-sectional area (by〜10%) and strength occurred, and analyses for biopsy samples (v.lateralis) were made in a well-matched condition. Both type I and II fibers showed hypertrophy, though type II fibers tended to show a larger increase in CSA. DNA microarray analysis showed that expressions of IGF-I/II, follistain-like peptide, caveolin and extracellular matrix-related proteins increased, whereas that of myostatin considerably decreased. The results suggest that reduced oxygen delivery during exercise plays an important part and affects the factors relating to the proliferation of muscle satellite cells. Less

我们以前显示的张力会导致肌肉大小和强度的辛克酶，并以中度的血管效率促进其机制。运动模型（动物和人类模型）。所有类型的纤维（I类型I，IIA和IIB/X）的横截面区域（CSA）都增加了。肝细胞生长因子（HGF）增加，NOS-1的表达增加，而i的表达却倾向于o在人类模型中的视力升高。每天两次进行2周（约10％），并发生了强度，并且对活检样品进行了分析（V.Lateralis在匹配良好的情况下进行。阵列分析表明，IGF-I/II的表达像肽一样，小窝蛋白和外部基质蛋白在运动过程中增加。