Mechanisms of Absorption, Transport and Tissue Uptake of RRR-α-Tocopherol and d-γ-Tocopherol in the White Rat
Mechanisms of Absorption, Transport and Tissue Uptake of RRR-α-Tocopherol and d-γ-Tocopherol in the White Rat
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RRR-α-生育酚和 d-γ-生育酚在白鼠体内的吸收、转运和组织摄取机制
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
R. Madère
中科院分区：
文献类型：
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作者：
W. Behrens;R. Madère
研究了三组大鼠α -和γ -生育酚的代谢，这些大鼠分别饲喂含有正常（NE， 0.2 g α -生育酚/kg）、高（HE， 1.0 g α -生育酚/kg）或低（LE，小于0.02 α -生育酚/kg）维生素E的改良AIN-76日粮3个月。在血浆和组织中测量了这两种维生素的水平，在某些情况下，在肝脏分离的微粒体和线粒体部分中也测量了这两种维生素的水平。口服20毫克γ -生育酚24小时后，血浆和组织中的α -生育酚水平保持不变，在α -生育酚水平较低的组织（如LE组）中发现较高的α -生育酚水平。尽管如此，在所有组织中的γ -生育酚水平下降2和3天后，它仍能保持在那里。当与α -生育酚联合服用时，γ -生育酚的水平低于单独服用时。LE组大鼠肝脏微粒体和线粒体结合α -生育酚的量分别是相同剂量α -或γ -生育酚的5倍和9倍。这些数据表明，调节维生素E代谢的机制对α -生育酚具有高度特异性。此外，α -生育酚的相对量决定了组织中γ -生育酚的水平。然而，组织中γ -生育酚的保留并不依赖于α -生育酚的存在。（摘要删节250字）
The metabolism of alpha- and gamma-tocopherol was studied in three groups of rats that were fed a modified AIN-76 diet containing normal (NE, 0.2 g alpha-tocopherol/kg), high (HE, 1.0 g alpha-tocopherol/kg) or low (LE, less than 0.02 alpha-tocopherol/kg) vitamin E for 3 mo. After 1, 2 and 3 d of an oral dose of 20 mg of alpha-tocopherol, gamma-tocopherol or both, the levels of the two vitamers were measured in plasma and tissues and in some cases in isolated microsomal and mitochondrial fractions from liver. Twenty-four hours after an oral dose of 20 mg gamma-tocopherol the levels of alpha-tocopherol in plasma and tissues remained constant and higher levels of gamma-tocopherol were found in tissues in which low alpha-tocopherol levels could be found such as in the LE group. In spite of this, it was enabled to remain there, after 2 and 3 d gamma-tocopherol had decreased levels in all tissues. When given in combination with alpha-tocopherol, the levels of gamma-tocopherol were lower than when gamma-tocopherol was given alone. Microsomes and mitochondria from livers of LE group bound five and nine times more alpha-tocopherol than gamma-tocopherol in rats dosed with equal amount of alpha- or gamma-tocopherol, respectively. These data indicate that the mechanisms that regulate the metabolism of vitamin E are highly specific for alpha-tocopherol. Moreover, the relative amount of alpha-tocopherol determined the levels of gamma-tocopherol in tissues. However, the retention of gamma-tocopherol in tissues did not depend on the presence of alpha-tocopherol.(ABSTRACT TRUNCATED AT 250 WORDS)