Molecular mechanisms of electrical stimulation for prevention of muscle atrophy

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H04041
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 59010:Rehabilitation science-related
• Research Institution: Nippon Sport Science University
• Principal Investigator: Nakazato Koichi 日本体育大学, 保健医療学部, 教授 (00307993)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 骨格筋萎縮 / 電気刺激 / ミトコンドリア / リボソーム

Outline of Final Research Achievements

The prevention of skeletal muscle atrophy, including sarcopenia, is an urgent issue. Skeletal muscle electrical stimulation (EMS) may effectively prevent skeletal muscle atrophy, especially for those who have difficulty exercising. However, the molecular mechanism is not necessarily clear. In this study, we found that (1) low-frequency EMS induces skeletal muscle contraction, mainly consisting of twitch contractions, and suppresses muscle atrophy caused by denervation, suggesting an increase in mitochondrial biosynthesis and quantity as the molecular mechanism. (2) High-frequency EMS-induced skeletal muscle contractions, mainly tetanic contractions, which suppressed muscle atrophy due to denervation as in the low-frequency study. However, it was concluded that the molecular basis for this was an increase in ribosome quantity, not mitochondria.

Free Research Field

筋生理学

Academic Significance and Societal Importance of the Research Achievements

加齢や病気によって筋肉が失われることは力の低下につながり歩行などの日常動作を困難にします。加齢や病気によって筋肉が失われるような人はそもそも筋肉量を維持するための運動も困難である場合が多く、運動の代わりになる骨格筋電気刺激は有望視されています。ただしその処方は基礎研究が乏しいのが現状です。電気刺激は電気の周波数（ヘルツ）によって異なり、低周波ではぴくっとした収縮、高周波では力強い収縮が導かれます。今回の研究では低周波、高周波ともに筋萎縮効果があることがわかりましたが、そのメカニズムが異なることも明らかになりました。本研究の成果は根拠に基づいた電気刺激の処方につながると言えます。