ヒトにおける実験的なハイパーホモシストの貧血によって引き起こされる内皮機能障害における酸化ストレスによる役割
P M Kanani1, C A Sinkey, R L Browning
1Departments of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
Circulation
|September 14, 1999
まとめ
メチオニンによって誘発されるホモシステインのレベルが上昇すると,健康な個体では血管機能が急速に低下します. 酸化ストレスの増加に関連したこの内皮機能障害は,動脈硬化症と高血圧に寄与する可能性があります.
科学分野:
- 心血管科学 心血管科学
- 血管生物学 血管生物学
- 人間の生理学 人間生理学
背景:
- 血ホモシステインの適度な上昇は,動脈硬化症と高血圧に関連しています.
- この研究では,ホモシステインが内皮機能と酸化ストレスに影響を及ぼすかどうかを調査しています.
研究 の 目的:
- ホモシステインのレベルを実験的に増加させることで,抵抗と導管の血管の内皮機能不全を引き起こすかどうかを判断する.
- ホモシステイン誘発の内皮機能不全における酸化ストレス (oxidant stress) の役割を調査する.
主な方法:
- 健康な被験者はL-メチオニンを投与して,高同位素菌血症を誘発した.
- 内皮機能は,前腕のアセチルコリンへの血管拡張と,フロー媒介の腕動脈の拡張を介して評価されました.
- アスコルビック酸 (抗酸化物質) が内皮機能に及ぼす効果を評価した.
主要な成果:
- メチオニンは,アセチルコリンへの前腕抵抗血管の拡張を著しく低下させた.
- 流れ媒介の膨張で測定された管道血管内皮機能も著しく低下しました.
- アスコルビック酸の投与は,メチオニン誘発の内皮機能不全を予防しました.
結論:
- 実験的に高濃度のホモシステインは,ヒトのレジスタンス血管と導管血管の両方の内皮機能を急速に損なう.
- この機能障害は,ホモシステイン,動脈硬化,高血圧の関連性を説明する可能性がある.
- 酸化ストレスの増加は,ホモシステインの有害な内皮効果に関連しています.
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