Diplock A T
Ciba Found Symp. 1983;101:45-55. doi: 10.1002/9780470720820.ch4.
The view that vitamin E functions in living systems primarily as a lipid antioxidant and free-radical scavenger has gained widespread acceptance. As a result of a large recent increase in knowledge of the potentially damaging effects of certain oxygen metabolites, the role of vitamin E can now be placed in context as one factor in a complex protective system that includes superoxide dismutase, catalase, and peroxidases, including the seleno-enzyme glutathione peroxidase. alpha-Tocopherol is presumed to occur in association with intracellular membranes, but the techniques on which this presumption was based have been insufficiently sensitive to allow its confident acceptance. The hypothesis that the unique molecular structure of the phytyl side-chain of alpha-tocopherol enables specific physicochemical interactions with arachidonyl residues of membrane phospholipids can explain how molecules of alpha-tocopherol are bound within biological membranes. The interaction between alpha-tocopherol and unsaturated phospholipids has been studied using a tissue culture technique. The results suggest that alpha-tocopherol is capable of exerting a controlling influence upon the linoleyl and arachidonyl residues within membrane phospholipids which cannot be explained on the basis of the antioxidant function of the vitamin, and which may provide evidence for the above hypothesis.
维生素E在生物系统中主要作为脂质抗氧化剂和自由基清除剂发挥作用的观点已得到广泛认可。由于最近对某些氧代谢产物潜在破坏作用的了解大幅增加，维生素E的作用现在可以作为一个复杂保护系统中的一个因素来理解，该系统包括超氧化物歧化酶、过氧化氢酶和过氧化物酶，包括含硒酶谷胱甘肽过氧化物酶。α-生育酚被认为与细胞内膜有关，但得出这一推测所依据的技术灵敏度不够，无法令人信服地接受这一推测。α-生育酚植基侧链的独特分子结构能够与膜磷脂的花生四烯酰残基发生特定物理化学相互作用的假说，可以解释α-生育酚分子如何结合在生物膜内。已使用组织培养技术研究了α-生育酚与不饱和磷脂之间的相互作用。结果表明，α-生育酚能够对膜磷脂中的亚油酰基和花生四烯酰基残基施加控制影响，这无法基于维生素的抗氧化功能来解释，并且可能为上述假说提供证据。
