ANTIOXIDANT PROTECTION BY HEMOPEXIN OF HAEM-STIMULATED LIPID-PEROXIDATION
ANTIOXIDANT PROTECTION BY HEMOPEXIN OF HAEM-STIMULATED LIPID-PEROXIDATION
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DOI：
10.1042/bj2560861
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发表时间：
1988-12-15
影响因子：
4.1
通讯作者：
SMITH, A
中科院分区：
文献类型：
--
作者：
GUTTERIDGE, JMC;SMITH, A
血红素（亚铁原卟啉 IX）是一种反应性低分子量形式的铁，能够参与氧自由基反应，从而导致蛋白质、脂质、碳水化合物和 DNA 的降解。组织损伤时可能会发生氧自由基反应。细胞外液依赖于与细胞内不同的抗氧化机制，循环蛋白质通过将促氧化形式的铁转化为反应性较低的形式来限制自由基反应。在测试的化合物中，只有脱氧血红素和断链抗氧化剂丁基羟基甲苯抑制（抑制超过 90%）血红素刺激的过氧化反应，通过共轭二烯的形成、亚麻酸中的硫代巴比妥酸反应物质或过氧化诱导的磷脂荧光来测量。结合珠蛋白（血红蛋白结合血清蛋白）无效。相反，只有触珠蛋白显着抑制血红蛋白刺激的脂质过氧化。铁盐诱导的脂质过氧化仅被脱铁转铁蛋白和铁螯合剂去铁胺抑制。所有脂质过氧化均被自由基清除剂丁基羟基甲苯和没食子酸丙酯抑制。这些发现支持了这样的概念：体内铁储备的运输和保存与抗氧化保护密切相关。
Haem (ferrous protoporphyrin IX) is a reactive low-molecular-mass form of iron able to participate in oxygen-radical reactions that can lead to the degradation of proteins, lipids, carbohydrates and DNA. Oxygen-radical reactions are likely to occur upon tissue damage. Extracellular fluids rely on antioxidant mechanisms different from those found inside in cell, and circulating proteins limit radical reactions by converting pro-oxidant forms of iron into less-reactive forms. Of the compounds tested, only apohaemopexin and the chain-breaking antioxidant butylated hydroxytoluene inhibited (by more than 90%) haemin-stimulated peroxidation as measured by formation of conjugated dienes, thiobarbituric acid-reactive material from linolenic acid or peroxidation-induced phospholipid fluorescence. Haptoglobin, the haemoglobin-binding serum protein, was ineffective. Conversely, only haptoglobin significantly inhibited haemoglobin-stimulated lipid peroxidation. Iron-salt-induced lipid peroxidation was inhibited only by apotransferrin and the iron-chelator desferrioxamine. All lipid peroxidations were inhibited by the radical scavengers butylated hydroxytoluene and propyl gallate. These findings support the concept that transport and conservation of body iron stores are closely linked to antioxidant protection.