Elucidation of neural mechanisms on plastic change of cardiovascular responses to nociceptive stimulation

2021 Fiscal Year Final Research Report

• Project/Area Number: 16K09006
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Pain science
• Research Institution: Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology
• Principal Investigator: Watanabe Nobuhiro 地方独立行政法人東京都健康長寿医療センター(東京都健康長寿医療センター研究所), 東京都健康長寿医療センター研究所, 研究員 (00540311)
• Project Period (FY): 2016-10-21 – 2022-03-31
• Keywords: 骨格筋 / 痛み / 循環機能 / 炎症

Outline of Final Research Achievements

Musculoskeletal disorders such as neck-shoulder stiffness and low back pain are one of chronic symptoms that many people suffer from. It has been reported that patients with chronic pain may also have cardiovascular dysfunctions such as orthostatic hypotension. The present study aimed to elucidate plastic change of cardiovascular response to skeletal muscle pain and its neural mechanisms, particularly focusing on inflammation which is related to pain chronicity.
Experiments were performed on anesthetized rats. To induce inflammation in skeletal muscles, carrageenan solution was intramuscularly injected a day before experiment. Pressure stimulation applied to rat's calf altered heart rate and blood pressure. When pressure stimulation was applied to an inflamed calf, increases in heart rate and blood pressure were exaggerated. Additionally, the contribution of cardiac sympathetic efferent nerves to such cardiovascular responses was suggested.

Free Research Field

自律神経生理学

Academic Significance and Societal Importance of the Research Achievements

肩こりや腰痛など筋骨格系の問題は多くの国民が抱える慢性症状のひとつである。加えて、慢性痛患者では、起立性低血圧などの自律神経症状を伴うことが知られている。一方、骨格筋の痛みが自律神経機能に影響を及ぼすメカニズムについてはよく分かっていない。炎症は慢性痛の誘因となる。したがって、骨格筋刺激により生じる循環反応（心拍数や血圧の変化）が筋肉の炎症により変化するという本研究の成果は、炎症が自律神経の機能調節を変化させることを示す科学的根拠を提供するものである。今後自律神経機能の変調を引き起こす原因を明らかにすることにより、慢性痛に伴う自律神経症状の病態解明が進むと考えられる。