Exploring Regulatory Mechanisms of Skeletal Muscle Microcirculation by Using Two-photon Laser Scanning Microscopy

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K13185
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Sports science
• Research Institution: Niigata University of Health and Welfare (2018-2019); The University of Electro-Communications (2017)
• Principal Investigator: Hotta Kazuki 新潟医療福祉大学, リハビリテーション学部, 講師 (30791248)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 骨格筋 / 微小循環 / ２光子レーザー走査型顕微鏡

Outline of Final Research Achievements

Capillary blood flow dramatically increases during exercise. We obtained 3-dimensional images of capillary blood flow of rat skeletal muscle by using two-photon laser scanning microscopy. Fluorescent dye was intravascularly administered to obtain the 3-D images. In normal skeletal muscle, the dye retained in the vessel for an hour after the administration; however, it leaked out from vessel in exercise-induced injured muscle. The amount of extravascular leakage, which indicates microvascular permeability, was elevated in injured muscle as compared to intact muscle. Vascular endothelial growth factor expression was enhanced in swelling myocytes and macrophage infiltrated myocyctes, concurrently with microvascular hyperpermeability. These results likely suggest that new insight of regulatory mechanism of skeletal muscle microcirculation by myocyte and capillary endothelium interacting each other.

Free Research Field

循環生理学，心臓リハビリテーション，理学療法学

Academic Significance and Societal Importance of the Research Achievements

骨格筋の毛細血管は，筋細胞との様々な物質交換を行う場です．本研究では，骨格筋の毛細血管は血管透過性（血管内外の物質移動のしやすさ）を調節していることを明らかにしました．運動によって損傷を受けた際に，血管透過性が高まり，血球成分などが間質へ漏出しやすくすることで，壊れた細胞の貪食を促進すると考えられました．逆に，再生筋が出現してくる回復期には血管透過性が低下し，再生筋の成熟を促すものと思われました．