機能するβ1-およびβ2-アドレノ受容体の共存は,人間の心室からの単一のミオサイトで示されています
F del Monte1, A J Kaumann, P A Poole-Wilson
1Department of Cardiac Medicine, National Heart and Lung Institute, London, England, UK.
Circulation
|September 1, 1993
まとめ
人間の心室筋細胞は,収縮のためにβ1およびβ2アドレノ受容体 (AR) の両方を利用する. エピネフリン濃度が低い場合,β2ARは主に心筋細胞の収縮反応を媒介する.
科学分野:
- 心臓病学 心臓病学
- 分子薬理学 分子薬理学
- 細胞生理学 細胞生理学
背景:
- 人間の心室は,β1-アドレノ受容体 (AR) とβ2-ARの両方を発現する.
- これらの亜型が心室筋細胞収縮に与える特定の貢献は,まだ完全に解明されていない.
研究 の 目的:
- ヒト単体心室筋細胞の収縮を調節するベータ1-ARとベータ2-ARの機能的役割を調査する.
- エピネフリンによって誘発される肌細胞収縮に対するβ1-ARとβ2-ARの相対的な貢献を決定する.
主な方法:
- ヒトの故障する心房と非故障する心房から単一の筋細胞を分離する.
- 選択性ベータ1-ARおよびベータ2-AR抗体 (CGP 20712AおよびICI 118,551,それぞれ) の存在または欠如において (-) - エピネフリンに対する濃度-反応曲線の構築.
- 収縮幅,速度,ピーク収縮までの時間,および50%のリラックスまでの時間の変化の評価.
主要な成果:
- (-) -エピネフリンは,ヒトの心室筋細胞における収縮幅と収縮速度を増加させた.
- (-) エピネフリンに対する反応は,β1-ARおよびβ2-ARブロッカーの両方によって逆行され,両方のサブタイプの異質な貢献を示しました.
- ベータ1-ARとベータ2-ARは,ピーク収縮とリラックスまでの時間の短縮に寄与しました.
- 低濃度の (-) - エピネフリンでは,ベータ2-ARは,特に心不全による筋細胞において,より支配的な役割を果たしているように見えた.
結論:
- ベータ1-ARとベータ2-ARは共存し,人間の心室筋細胞に機能的に活性化しています.
- 肌細胞収縮に対するβ1-ARとβ2-ARの相対的な貢献は,個々の細胞によって異なります.
- 衰弱した人間の心臓では,β2-ARは主に低濃度のエピネフリンに対する収縮反応を媒介する.
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