活性筋肉におけるインタースティシャルATPとノレピネフリン濃度
Jianhua Li1, Nicholas C King, Lawrence I Sinoway
1Division of Cardiology, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, 500 University Dr, Hershey, PA 17033, USA. jzl10@psu.edu
Circulation
|May 25, 2005
まとめ
運動は交感神経系の活動を高めます. 活発な筋肉では,高濃度のインタースティシャルアデノシントリホスファート (ATP) が交感神経のP2X受容体を刺激し,ノレピネフリン (NE) の放出を増やし,血圧を維持します.
科学分野:
- 生理学 生理学とは
- 神経科学は神経科学である.
- バイオケミストリー バイオケミストリー
背景:
- 交感神経系の活動とノレピネフリン (NE) は,運動中に血圧を維持するために不可欠です.
- 収縮する骨格筋はアデノシントリフォスファート (ATP) を放出し,交感神経はP2X受容体を持っています.
研究 の 目的:
- 骨格筋における高濃度のインタースティシャルATPがP2X受容体を刺激し,それによってインタースティシャルNE濃度が上昇するかどうかを調査する.
- ATPが収縮する筋肉と交感神経の間の信号分子の役割を果たすという仮説を検証する.
主な方法:
- 微細透析は,ネズミの骨格筋から間接液を採取するために使用されました.
- 高性能液体クロマトグラフィー (HPLC) でATPとNEの濃度が測定されました.
- 実験には,筋肉の伸縮,動脈内ATP注射,P2X受容体対抗剤 (PPADS) と核酸酶抑制剤 (ARL67156) の投与が含まれていました.
主要な成果:
- 筋肉のストレッチにより,インタースティシャルATP ([ATP]i) とNE ([NE]i) レベルが著しく上昇した.
- [NE]iの上昇は, [ATP]iの上昇と直接相関していた.
- ATP投与により,PPADSとARL67156によって調節される[NE]iが上昇し,P2X受容体の関与が確認されました.
結論:
- 骨格筋は収縮時にATPを放出し,交感神経のP2X受容体を刺激する.
- このATP媒介のシグナル伝達により,間接的なNE濃度が上昇し,運動中の血圧調節に貢献します.
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