Burton G W, Ingold K U, Cheeseman K H, Slater T F
Division of Chemistry, National Research Council of Canada, Ottawa, Ontario.
Free Radic Res Commun. 1990;11(1-3):99-107. doi: 10.3109/10715769009109672.
alpha-Tocopherol, a superior chain-breaking, peroxyl radical-trapping antioxidant and the most active component of vitamin E, is elevated in liver tumor cells, contributing to their greater resistance towards lipid peroxidation compared to cells from normal tissues. Also, in regenerating rat liver the level of vitamin E has been found to fluctuate in phase with the rate of cell division. In order to study the biokinetics and mechanisms of the distribution of vitamin E in organs and within tissues of animals, deuterated forms of alpha-tocopherol have been synthesized and their uptake into blood and tissues has been measured by gas chromatography-mass spectrometry. Measurement of the competitive uptake from a mixture of the RRR- and SRR-alpha-tocopherol stereoisomers labelled with different amounts of deuterium shows that the liver exerts a strong preference for secretion of the natural (RRR) stereoisomer into the plasma. It is suggested that a tocopherol-binding protein plays a key role in this process.
α-生育酚是一种卓越的链断裂、过氧自由基捕获抗氧化剂，也是维生素E中最具活性的成分，在肝癌细胞中含量升高，与正常组织来源的细胞相比，使其对脂质过氧化具有更强的抵抗力。此外，在大鼠再生肝脏中，已发现维生素E的水平与细胞分裂速率呈同步波动。为了研究维生素E在动物器官和组织中的生物动力学及分布机制，已合成了α-生育酚的氘代形式，并通过气相色谱-质谱法测定了它们在血液和组织中的摄取情况。对标记有不同量氘的RRR-和SRR-α-生育酚立体异构体混合物的竞争性摄取测量表明，肝脏对将天然（RRR）立体异构体分泌到血浆中具有强烈偏好。有人认为，生育酚结合蛋白在这一过程中起关键作用。
