Effects of respiratory muscle activation and cardiopulmonary baroreflex on cardiovascular regulation during exercise(Fostering Joint International Research)

2019 Fiscal Year Final Research Report

• Project/Area Number: 16KK0201
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Sports science
• Research Institution: Nagoya University
• Principal Investigator: Katayama Keisho 名古屋大学, 総合保健体育科学センター, 教授 (40343214)
• Project Period (FY): 2017 – 2019
• Keywords: 運動 / 血管運動神経活動 / 筋交感神経活動 / 呼吸筋 / 心肺圧受容器反射

Outline of Final Research Achievements

Work of breathing influences sympathetic vasomotor outflow during exercise. The subjects performed leg cycling at 40%, 60%, and 80% peak workload. At 60% and 80% cycling, proportional assist ventilator reduced work of breathing and muscle sympathetic nerve activity (MSNA). Lowering the normally occurring work of breathing during exercise results in commensurate reductions in MSNA. These results provide evidence of a sympathetically mediated vasoconstrictor effect emanating from respiratory muscles during whole body exercise.
Cardiopulmonary baroreflex control of sympathetic vasomotor outflow during exercise. MSNA was recorded during postexercise ischemia (PEI) after low- (PEI-L) and high- (PEI-H) intensity isometric exercise. PEI-L with leg cycling induced a significant decrease in MSNA, while PET-H with leg cycling did not decrease MSNA. These results suggest that cardiopulmonary baroreflex control of sympathetic vasomotor ouflow is attenuated by high metaboreflex activation.

Free Research Field

運動生理学

Academic Significance and Societal Importance of the Research Achievements

呼吸筋活動による運動時の循環調節．運動時の血圧調節に関係する血管運動神経活動に呼吸筋活動が影響していることが示された．この新しい知見は呼吸機能が低下している高齢者や呼吸循環器疾患患者において認められる動的運動時の過度の血圧上昇に，呼吸筋由来の代謝受容器反射が関係していることが推測される．
心肺圧受容器反射による運動時の循環調節．これまで解明されていなかった，運動時の筋ポンプ作用による心肺圧受容器反射を介した血管神経活動調節および筋代謝受容器反射との相互関係が明らかとなった．この結果は，運動時の循環調節メカニズムに新しい知見をもたらすものである．