運動に対する反応として冠動脈の酸化窒素生成と内皮依存性アゴニスト

J H Traverse¹, Y L Wang, R Du

¹Department of Medicine, Division of Cardiology, University of Minnesota Medical School, the VA Medical Center, and the Minneapolis Heart Institute, Abbott Northwestern Hospital, Minneapolis, Minn. 55455, USA.

Circulation

|June 1, 2000

まとめ

冠動脈の窒素酸化物 (NO) 産生は,アゴニストによって著しく増加しますが,運動中に最小限に増加します. これは,健康な心臓における運動による冠動脈血管拡張にNOが欠かせないことを示唆している.

科学分野:

心血管生理学心血管の生理学
運動生理学運動生理学
内皮機能の機能について

背景:

内皮に由来する酸化窒素 (NO) は,運動中に冠動脈の血管拡張を助長する.
しかし,NOブロックは,運動による冠動脈血流 (CBF) の増加を妨げることはありません.
これは,運動による冠動脈抵抗血管の膨張にはNOが必須ではないことを意味する.

研究の目的:

アゴニストによって刺激された冠動脈のNO産生が運動中のNO産生を上回るかどうかを判断する.
運動による冠動脈血管拡張におけるNOの役割を調査する.

主な方法:

犬の化学発光により血中の窒素酸塩+窒素酸塩 (NOx) を測定した.
トレードミルの運動およびアゴニスト注入 (アセチルコリン,ブラジキニン) 中のNOx生成を評価した.

主要な成果:

静止状態の冠動脈 NOx の有意な生成はなく,中程度の運動も行わない.
冠動脈 NOx 生成のわずかな増加は,最も高い運動強度でのみ観察されました.
冠動脈のNOx産生は,アセチルコリンとブラジキニンに反応して有意に増加した.

結論:

エンドセリウム依存性アゴニストによって刺激される冠動脈のNO生成は,運動に関連した切断ストレスによって誘発されるよりも大きい.
発見は,通常の運動による冠動脈血管拡張には,NOが必要とされていないことを支持しています.

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