心筋の酸素化は,心臓の高労働状態で,心臓の心臓発作後の再構築を伴う
1Departments of Medicine, Biochemistry, and Radiology and the Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.
Circulation
|February 23, 1999
まとめ
心筋梗塞後の左心室リモデリング (LVR) は,高エネルギーリン酸 (HEP) の減少につながります. この研究では,心臓機能不全の低HEPレベルは,心臓の労働負荷が増加したときにさえも,酸素の不足によるものではないことが判明しました.
科学分野:
- 心臓病学 心臓病学
- 心血管生理学 心血管の生理学
- バイオケミストリー バイオケミストリー
背景:
- 心筋梗塞後の左心室改造 (LVR) は,心筋高エネルギーリン酸 (HEP) 濃度の低下と関連しています.
- これらのHEPの減少は,充血性心不全 (CHF) を発症する動物ではより深刻です.
- 増加した心臓の労働負荷は,HEPの損失を悪化させ,需要誘発性不血症を示唆します.
研究 の 目的:
- 筋細胞の不十分な酸素供給が,心臓発作後のLVRとCHFにおけるHEP異常の原因であるという仮説を検証する.
- 基礎および刺激条件下における心筋酸素供給とHEPレベルとの関係を調査する.
主な方法:
- 豚における冠動脈連動によって誘発された心筋梗塞.
- グループには,正常な,補償されたLVR,CHFの動物が含まれていました.
- フォスフォクレアチン/ATP (PCr/ATP) は31P NMRで測定され,デオキシミオグロビン (Mb-デルタ) はリモート心筋で1H NMRで測定された.
主要な成果:
- 基礎PCr/ATPは心臓発作後の心臓に低下し,CHFでは有意に低下しました.
- ドブタミンは,正常な心臓とLVRの心臓でレート・プレッシャー・プロダクトを増加させ,検知可能なMb-deltaなしにPCr/ATPの比較可能な低下を引き起こした.
- CHFでは,ドブタミン反応は弱まり,Mb-delta.と関連していない.
結論:
- ドブタミンが誘発したPCr/ATP減少は,酸素の不足によるものではない.
- 低基礎PCr/ATPと低濃度のドブタミン反応は,心筋梗塞では心筋低血症なしに発生した.
- HEPおよびCHFの収縮異常は,酸素の不足によるものではない.
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