金属催化的多不饱和脂肪酸过氧化反应

Metal-catalyzed peroxidation of polyunsaturated fatty acids.

作者信息

Knight J A, McClellan L

机构信息

Department of Pathology, University of Utah School of Medicine, Salt Lake City 84132.

出版信息

Ann Clin Lab Sci. 1989 Sep-Oct;19(5):377-82.

PMID:2802516

Abstract

In this study malondialdehyde (MDA) was measured as the thiobarbituric acid (TBA) adduct by high performance liquid chromatography with linolenic acid (LA), as well as with LA to which the following metal ions were added: Ag+1, Al+3, As+5, Ba+2, Cd+2, Co+2, Cu+1, Cu+2, Fe+2, Fe+3, Hg+2, Mn+2, Ni+2, Pb+2, and Zn+2. Our results showed that Fe+3 is a particularly potent catalyst of this oxidation reaction. Several other metals also significantly increased the production of MDA over LA alone, as shown by the Mann-Whitney test, including Al+3 and Fe+2 (p less than 0.001), Cu+2, Ba+2, Mn+2 (p less than 0.01), and As+5 (p less than 0.05). Pb+2 almost completely inhibited the production of MDA from LA (p less than 0.001). Addition of the free radical scavenger, butylated hydroxytoluene (BHT), significantly inhibited MDA formation in these latter reactions, indicating they are free-radical mediated. Pre-incubation of the reaction mixtures at 37 degrees C and physiologic pH with both Fe+2 and Fe+3 greatly increased MDA formation, suggesting that in acute metal toxicity the initiating free-radical process might be primarily due to direct metal catalysis of preformed lipid peroxides.

摘要

在本研究中，通过高效液相色谱法，以亚麻酸（LA）以及添加了以下金属离子的LA来测定丙二醛（MDA）作为硫代巴比妥酸（TBA）加合物：Ag⁺¹、Al⁺³、As⁺⁵、Ba⁺²、Cd⁺²、Co⁺²、Cu⁺¹、Cu⁺²、Fe⁺²、Fe⁺³、Hg⁺²、Mn⁺²、Ni⁺²、Pb⁺²和Zn⁺²。我们的结果表明，Fe⁺³是该氧化反应特别有效的催化剂。如曼-惠特尼检验所示，其他几种金属也显著增加了仅LA时MDA的生成量，包括Al⁺³和Fe⁺²（p小于0.001）、Cu⁺²、Ba⁺²、Mn⁺²（p小于0.01）和As⁺⁵（p小于0.05）。Pb⁺²几乎完全抑制了LA生成MDA（p小于0.001）。添加自由基清除剂丁基羟基甲苯（BHT）显著抑制了这些后续反应中MDA的形成，表明它们是自由基介导的。将反应混合物在37℃和生理pH下与Fe⁺²和Fe⁺³预孵育极大地增加了MDA的形成，这表明在急性金属中毒中，引发自由基过程可能主要是由于预先形成的脂质过氧化物的直接金属催化作用。