潜在的に致癌性であるペロキシクロミウム ((IV) とグルタチオンを含むクロミウム還酸化サイクル
Roberto Marin1, Yachna Ahuja, Rathindra N Bose
1Department of Biomedical Sciences, Ohio University, Athens, Ohio 45701, USA.
Journal of the American Chemical Society
|August 5, 2010
まとめ
クロミウム (VI) 複合体は,グルタチオンと酸素を含む周期的な酸化還元プロセスを誘発し,継続的なクロミウム (VI) とクロミウム (IV) のリサイクルにつながります. このサイクルにより,DNAにダメージを与えるクロームの中間物質が生成され,クロームの発がんに寄与する.
科学分野:
- バイオケミストリー バイオケミストリー
- 毒理学 毒理学 毒理学
- 無機化学 無機化学とは
背景:
- クロミウム (VI) は,DNA損傷と変異性に関与しているクロミウム (IV) 複合体が知られている発がん物質です.
- クロミウム種のリドックスサイクルを理解することは,クロミウム誘発の毒性のメカニズムの解明に不可欠です.
研究 の 目的:
- クロミウム ((IV) -ペロキソ複合体とグルタチオンの間の反応機構を中性pHで調査する.
- レドックスサイクル中に形成されるクロム中間物質の特徴を記述する.
- これらの中間物質のDNA損傷の可能性を評価する.
主な方法:
- アクアエチレンダイアミンビス (((ペロキソ) クロミウム (((IV)) とグルタチオンの反応運動学的研究.
- クロミウム (V) とクロミウム (IV) の中間物質のスペクトル学的特徴.
- 単一鎖断裂およびDNA酸化測定を用いたDNA損傷の評価.
主要な成果:
- 周期的な酸化還元過程が観察され,Cr (IV) とCr (VI) がCr (V) の中間物質で継続的にリサイクルされる.
- グルタチオンの調整により,Cr (IV) からCr (VI) への自己酸化が誘発され,Cr (V) 経由でCr (IV) への還元が続いた.
- 特徴づけられた中間物質には,DNA単一鎖の断裂と酸化を誘導するモノ-およびビスグルタチオナトクロミウム複合体が含まれていた.
結論:
- この反応は,グルタチオンと分子酸素によって促進される自己持続的なクローム・レドックスサイクルを生成します.
- この絶え間ない循環は,DNAにダメージを与えるクロミウム種を産生し,クロミウム (VI) 媒介による細胞環境における発癌のメカニズムを示唆する.
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