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本文论及硒的生物学作用和硒与其他营养素(包括微量元素)相互作用的最新知识,以及硒在人体营养和健康中的重要性。已证明硒是谷胱甘肽过氧化物酶(glutathione peroxidase)的组成部分,此酶可催化还原大量脂质氢过氧化物和过氧化氢。维生素E,硒和多不饱和脂肪酸之间存在着复杂的相互关系。第一,谷胱甘肽过氧化物酶中的硒可控制细胞内过氧化氢的水平,而过氧化氢可影响作为脂质过氧化作用引发剂的活泼氧代谢物的形成,硒的这种作用又与超氧化物岐化酶(Superoxide dismutase)的作用密切有关,此酶控制了细胞内超氧化物阴离子(Superoxide anion)的水平。第二,维生素E通过它的抗氧化功能控制脂质氢过氧化物的形成,并可能与膜磷脂有结构上的联系。第三,由膜磷脂形成的脂质氢过氧化物可被谷胱甘肽过氧化物酶催化还原成羟基酸而不损伤细胞内各系统。在人体营养领域中,已表明硒缺乏是一种在中国发生的心肌病——克山病的发病因素,与之世界上其他三个地区的血硒水平相比较,克山病地区人群血硒水平明显低于那些地区。克山病首次证明硒是一种人类必需的微量元素。
This article discusses the biological role of selenium and the latest knowledge of the interaction of selenium with other nutrients, including trace elements, and the importance of selenium in human nutrition and health. Selenium has been shown to be part of glutathione peroxidase, an enzyme that catalyses the reduction of large quantities of lipid hydroperoxides and hydrogen peroxide. There is a complex relationship between vitamin E, selenium and polyunsaturated fatty acids. First, selenium in glutathione peroxidase can control the level of intracellular hydrogen peroxide that can affect the formation of active oxygen metabolites as lipid peroxidation initiators, and this selenium In turn, it is closely linked to the action of Superoxide dismutase, which controls the level of Superoxide anion in cells. Second, vitamin E controls lipid hydroperoxide formation through its anti-oxidant function and may be structurally linked to membrane phospholipids. Third, lipid hydroperoxides formed by membrane phospholipids can be catalytically reduced by glutathione peroxidase to hydroxy acids without damaging intracellular systems. In the field of human nutrition, it has been shown that selenium deficiency is a cardiomyopathy occurring in China - the risk factor for Keshan disease. Compared with blood selenium levels in the other three regions of the world, blood selenium in Keshan disease The level is significantly lower than those areas. Keshan disease for the first time that selenium is a human trace element.