アラキドン酸とイコサノイドの鉄過量カルディオミオサイトにおける放出の増加

R Mattera¹, G P Stone, N Bahhur

¹Rammelkamp Center for Education and Research, MetroHealth Medical Center, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA. matterar@helix.nih.gov

Circulation

|May 23, 2001

まとめ

心臓細胞の鉄過負荷は,アラキドン酸 (AA) の放出を増加させ,その代謝を変化させ,潜在的に心拍の問題を引き起こします. この研究では,心筋細胞におけるこれらの変化を調査した.

科学分野:

心血管生物学心血管生物学
細胞の代謝について
毒理学毒理学毒理学

背景:

輸血による鉄過負荷は,生命を制限する心筋病に繋がる可能性があります.
脂質代謝酵素は過酸化性損傷に対して敏感である.
アラキドン酸 (AA) とその代謝産物は,心臓のリズムに影響します.

研究の目的:

鉄過負荷の心筋細胞が,アラキドン酸 (AA) の放出と前立腺素の産生が変化しているかどうかを調査する.
これらの変化の背後にあるメカニズムを探求する.

主な方法:

ネズミの新生児の心室筋細胞 (NRVM) は,鉄過負荷を誘発するために,鉄氨酸酸酸で培養された.
アラキドン酸 (AA) の放出,フォスフォリピドへの組み込み,エコサノイド産生を測定した.
特定の酵素阻害剤の効果を評価した.

主要な成果:

鉄過負荷は,静止状態と刺激状態のNRVMでAAの放出を大幅に増加させた.
鉄処理は,フォスファディチルコレンの種にAAの分布を変化させ,イコサノイドの産生を増加させた.
AA放出量の増加は,フォスホリパゼA(2) やCによるものではなく,ダイアシルグリセロールリパゼによって媒介された.

結論:

鉄過負荷は,NRVMにおけるAA放出,フォスファディチルコレンの組み込み,サイクロオキシゲネーゼ-2誘導,およびエコサノイド生成を強化する.
これらの発見は,AA代謝産物と,鉄過負荷誘発性心筋病で観察された電気機械的変化の間の関連性を示唆しています.

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