Effect of muscle contraction mode on intracellular signaling-related muscle hypertrophy

• Project/Area Number: 24700703
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Sports science
• Research Institution: Juntendo University
• Principal Investigator: KAKIGI RYO 順天堂大学, 医学部, 助教 (70614931)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2013: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 筋収縮様式 / 細胞内シグナル伝達 / 筋線維組成 / 筋肥大 / レジスタンス運動 / タンパク質合成 / 筋線維タイプ / 筋タンパク質合成 / トレーニングステータス

Outline of Final Research Achievements

The aim of this study was to clarify the effect of muscle contraction mode on intracellular signaling involved in protein synthesis and muscle hypertrophy in human skeletal muscle. We demonstrated that maximal eccentric muscle contraction exercise rather than concentric and isometric contraction exercise stimulates mammalian target of rapamycin (mTOR) signaling in untrained skeletal muscle. In addition, the increase of mTOR signaling after eccentric contraction occurred mainly in Type I and IIa muscle fiber. These results suggest that training with eccentric contraction may be effective methods to increase muscle protein synthesis and muscle mass in the early phase of exercise intervention.

Research Products

• [Journal Article] Whey protein intake after resistance exercise activates mTOR signaling in a dose-dependent manner in human skeletal muscle (2014)
  • Author(s): Kakigi R, Yoshihara T, Ozaki H, Ogura Y, Ichinoseki-Sekine N, Kobayashi H, Naito H
  • Journal Title: European Journal of Applied Physiolgy Volume: 114 Issue: 4 Pages: 735-742
  • DOI: 10.1007/s00421-013-2812-7
  • Peer Reviewed
• [Journal Article] Effects of walking combined with restricted leg blood flow on mTOR and MAPK signaling in young men (2014)
  • Author(s): Ozaki H, Kakigi R, Kobayashi H, Loenneke JP, Abe T, Naito H
  • Journal Title: Acta Physiologica Volume: (印刷中) Issue: 1 Pages: 97-106
  • DOI: 10.1111/apha.12243
  • Peer Reviewed
• [Presentation] Eccentric muscle contraction stimulates mTOR signaling in human skeletal muscle (2015)
  • Author(s): Kakigi R, Naito H, Yoshihara T, Ichinoseki-Sekine N, Okada T.
  • Organizer: The 92nd Annual Meeting of The Physiological Society of Japan
  • Place of Presentation: Kobe, Japan
  • Year and Date: 2015-03-21 – 2015-03-23
• [Presentation] 伸張性収縮運動によるヒト骨格筋mTORシグナルの増加は鍛練度によって異なる (2014)
  • Author(s): 柿木亮、内藤久士、吉原利典、坂本彰宏、中村智洋、小林裕幸、岡田隆夫
  • Organizer: 第69回日本体力医学会大会
  • Place of Presentation: 長﨑、日本
  • Year and Date: 2014-09-19 – 2014-09-21
• [Presentation] Submaximal cycling exercise stimulates mTOR signaling pathway in human skeletal muscle. (2013)
  • Author(s): Kakigi R, Naito H, Yoshihara T, Ozaki H, Kobayashi H, Okada T.
  • Organizer: Experimental biology 2013
  • Place of Presentation: Boston, USA.
• [Presentation] 最大下自転車運動によるヒト骨格筋Akt/mTORシグナル伝達の経時変化 (2013)
  • Author(s): 柿木亮、内藤久士、吉原利典、尾崎隼朗、都築孝允、小林裕幸、岡田隆夫
  • Organizer: 第58回日本体力医学会大会
  • Place of Presentation: 教育会館（東京）、日本
• [Presentation] ラット骨格筋の過負荷によるmTORシグナル伝達経路の活性化に持久性運動における強度の違いが及ぼす影響 (2013)
  • Author(s): 尾崎隼雄、柿木亮、内藤久士
  • Organizer: 第58回日本体力医学会大会
  • Place of Presentation: 教育会館（東京）、日本
• [Presentation] 男性短距離走者の骨格筋におけるACTN3タンパク質発現量と筋線維組成 (2013)
  • Author(s): 中村智洋、柿木亮、関根紀子、小林裕幸、佐久間和彦、内藤久士
  • Organizer: 第58回日本体力医学会大会
  • Place of Presentation: 教育会館（東京）、日本
• [Presentation] Whey protein ingestion after exercise decreases LC3-II expression in human muscle. (2012)
  • Author(s): Kakigi R.
  • Organizer: 15th International Biochemistry of Exercise Conference.
  • Place of Presentation: Stockholm, Sweden.
• [Presentation] Effects of whey peptide ingestion after resistance exercise on mTOR signaling in human skeletal muscle. (2012)
  • Author(s): Kakigi R.
  • Organizer: The American College of Sports Medicine 59th Annual Meeting.
  • Place of Presentation: Sanfrancisco, USA.