未成熟のウサギの心臓における予備条件付け:KATPチャネルの役割
J E Baker1, P Holman, G J Gross
1Division of Cardiothoracic Surgery, Department of Pharmacology and Medical College of Wisconsin, Milwaukee, USA. jbaker@mcw.edu
Circulation
|March 9, 1999
まとめ
未成熟の心臓は,予備条件付けによって傷害から保護することができますが,出生から慢性的な低酸素症に曝されない場合にのみです. この心臓保護効果には,KATPチャネルが関与しています.
科学分野:
- 心血管生理学 心血管の生理学
- 新生児心臓科 新生児心臓科
- 発血不全の予備条件付け
背景:
- 缺血的予備条件は,種を超えて成人の心臓に保護を提供します.
- 未成熟の心臓の予備条件付けの可能性,その持続時間,およびその背後にあるメカニズムについては,まだあまり理解されていません.
研究 の 目的:
- ノルモキシカルまたは慢性的な低酸素状態の未熟な心臓が,予備条件付けを受けることができるかどうかを調査する.
- この心臓保護効果の時間窓とKATPチャネルの役割を決定する.
主な方法:
- 隔離された未成熟ウサギの心臓 (7-10日) は,予備条件付けのために,異なったイシュケミア/再注血のサイクルを施した.
- その後,心臓はより長い不血症期に曝され,回復は左心室の発達圧によって測定された.
- KATPチャネル遮断と異なる再注射時間の効果を評価した.
主要な成果:
- ノルモキシクスの未熟な心臓は,1回の予備条件付けサイクル後に有意な回復を示し,3回のサイクルから追加の利益はありませんでした.
- 慢性的に低酸素の未熟な心臓は,前置条件付き対照群と比較して,前置条件付きで回復が向上しなかった.
- プリコンディショニング後の回復期間が30分に延長されたとき,心臓保護は失われました.
- KATPのチャネルブロックは,ノルモキシカルハートにおける前置条件効果を無効にしました.
結論:
- ノルモキシカルな環境からの未熟な心臓は,前もって条件付けすることができます.
- 生まれてから慢性的な低酸素症に曝された未熟な心臓は,効果的に前置条件付けができない.
- KATPチャネルは,ノルモキシクスの未熟な心臓の予備条件付けに関与しています.
関連する概念動画
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