短期性イシュケミアの影響: 麻酔,予備条件付け,およびその臨床的影響: 第2部

R A Kloner¹, R B Jennings

¹Heart Institute, Good Samaritan Hospital, Keck School of Medicine, University of Southern California, Los Angeles, USA. rkloner@goodsam.org

Circulation

|December 19, 2001

まとめ

短期のイシュケミアは,麻酔を介して心臓に害を与え,長期的な機能障害を引き起こす可能性があります. しかし,また,不血性予備条件を介して心臓を保護し,その後のイベントからの損傷を軽減します.

科学分野:

心血管生理学心血管の生理学
発血性心臓病発血性心臓病発血性心臓病発血性心臓病とは

背景:

15分までの心筋不全は,可逆的な損傷を引き起こすが,麻痺した心筋のような持続的な変化を誘導する.
麻痺は酸素の急性,カルシウムホメオスタシスの変化,および潜在的に収縮性タンパク質の変化を伴うため,後発血性機能障害を引き起こす.
臨床的シナリオには,血管新生手術,不安定な胸痛,心肺バイパス後,麻痺した心筋が機能を損なうなどがあります.

研究の目的:

短期的な心筋梗塞不全症の二重効果:有害な"麻痺"と保護的な"不全症の予備条件付け"を探求する.
心筋麻痺と不血性予備状態の背後にあるメカニズムを調査する.
これらの現象を管理するための臨床的影響と将来の治療戦略について議論する.

主な方法:

犬における冠動脈閉塞に関する実験的研究.
様々な臨床環境での麻痺した心筋膜の観察.
酸素ラジカル,カルシウムホメオスタシス,アデノシン,タンパク質キナーゼC,ATP依存のカリウムチャネルを含むメカニズムのレビュー.

主要な成果:

短時間のイシュケミア (最大15分) は,可逆性筋細胞損傷を引き起こすが,長期にわたる収縮機能不全と麻痺した心筋につながる.
短時間 (5分) のエピソードであっても,イシュケミアの予備条件付けは,その後の長期のイシュケミアによる死滅を大幅に軽減します.
証拠によると,先制化はヒトでも起こりうることが示唆されており,これは,胸の痛み症状の減少と,心臓生検における特定の代謝変化によって示されている.

結論:

短期のイシュケミアにはパラドックスな効果があります:心筋麻痺 (陰性) と心筋不全の予備条件付け (陽性).
これらのメカニズムを理解することは,麻痺を最小限に抑え,予備条件を最大限に高めるための治療法の開発に不可欠です.
予備条件付け経路をターゲットとする将来の薬理学的薬剤は,不血症に対する新しい治療アプローチを提供します.

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