メカノレフレクスは,心不全における過剰な運動圧力反射を媒介する
Scott A Smith1, Jere H Mitchell, R Haris Naseem
1Department of Internal Medicine, Harry S. Moss Heart Center, University of Texas Southwestern Medical Center, Dallas, TX 75390-9174, USA.
Circulation
|October 12, 2005
まとめ
心不全では,グループIVアファレントニューロンではなく,筋肉のメカニコレフレクスが,過剰な運動圧力反射反応を駆動します. これは,メカノレフレクスをターゲットにすることで,心不全における異常な運動反応を治療できると示唆しています.
科学分野:
- 心血管生理学 心血管の生理学
- 運動生理学 運動生理学
- 心不全に関する研究
背景:
- 心不全は,運動中の平均動脈圧 (MAP) と心拍数 (HR) の過大な増加によって特徴付けられます.
- この過剰な心血管反応は,過度に活発な運動圧力反射 (EPR) によって媒介されます.
- グループIVアフェレントニューロンが誇張されたEPRを開始する一方で,それらは強化された循環反応を媒介するものではありません.
研究 の 目的:
- 主にIIIグループアフェレント繊維を含むEPRの機械的に敏感な成分が,心不全における拡張EPRを媒介するという仮説を検証する.
主な方法:
- 拡張性心筋症 (DCM) のラットモデルと対照 (偽) グループを使用した.
- グループIVのアフェレント繊維は,新生児キャプサイシン治療 (NNCAP) 動物で切除されました.
- EPRは,ガドリニウム (機械受容体阻害物質) を含んだり含まないように,電気的に誘発された静的な筋肉収縮によって活性化されました.
主要な成果:
- DCMとNNCAPのネズミは,偽ネズミと比較して,EPRの活性化中にMAPとHRのより大きな増加を示した.
- ガドリニウム投与は,すべてのグループで収縮に対するMAPとHRの反応を弱めた.
- 応答の減少は,DCMとNNCAPのラットでは著しく大きく,メカニカル受容体への依存度が高いことを示しました.
結論:
- 筋肉の機械反射は,心不全における過剰な運動圧力反射の主要な媒介である.
- メカノレフレクスの過剰活動は,変化したグループIV繊維機能の補償メカニズムである可能性があります.
- 筋肉のメカニコレフレクスは,心不全における異常な運動誘発循環器反応の管理のための新たな治療的標的となる可能性がある.
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