ヒステレス効果は,リポラライゼーションのメカニズムとしてカルシウム循環を意味する
Mariah L Walker1, Xiaoping Wan, Glenn E Kirsch
1Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, 2500 MetroHealth Dr, Hamman 330, Cleveland, Ohio 44109-1998, USA.
Circulation
|October 29, 2003
まとめ
心拍数が減速した後にアルテランが持続する現象であるT波アルテランヒステレシスは,心筋細胞の固有の特性である. これは,細胞内カルシウム循環がアルターナンスのメカニズムと突然の心臓死リスクの鍵であることを示唆しています.
科学分野:
- 心臓病学 心臓病学
- 電気生理学 電気生理学
- 細胞生物学 細胞生物学
背景:
- リポラライゼーションの不安定性のマーカーであるT波のアルターナンスは,突然の心臓死に関連しています.
- T波の代替が心拍数低下後も持続するヒステリーシス効果は,患者で観察されています.
研究 の 目的:
- T波の交代がヒステリシスであるかどうかを調査する.ヒステリシスは心筋細胞の固有の特性である.
- 細胞内カルシウム循環が,アルターナンスのヒステレシスのメカニズムにおける役割を調査する.
主な方法:
- ランゲンドルフが浸透したコウモリの心臓は,光学的なアクションポテンシャルが記録され,代替を誘導するためにペースが設定されました.
- 全細胞パッチクランプの電気生理学は,BAPTA-AM (カルシウムケレーター) を含むまたは含まない,単離された心筋細胞に実施されました.
主要な成果:
- アルターナンスのヒステリーシスは,孤立した心臓で一貫して観察され,アルターナンスは減速時に心拍数が著しく低下し続けました.
- 光学マッピングにより,空間的に不協和な変数の値におけるヒステリシスが明らかになった.
- BAPTA-AMによるカルシウムケレーションにより,投与量に依存して,アルターナンスの値が上昇し,ベースラインのアクションポテンシャルの持続時間に影響を与えることなくヒステレシスが抑制されました.
結論:
- Alternans hysteresisは,心筋細胞の固有の特性である.
- このヒステリーシスは,心拍数正常化後の心拍数変異剤の持続的な発作につながる可能性があります.
- 細胞内カルシウム循環は,T波の交替の基礎となるメカニズムにおいて重要な役割を果たします.
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