Reversal by Bile Acid on the Inhibition of α-Tocopherol Absorption by Retinoic Acid
Reversal by Bile Acid on the Inhibition of α-Tocopherol Absorption by Retinoic Acid
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胆汁酸逆转视黄酸对 α-生育酚吸收的抑制
DOI：
10.1093/jn/112.2.401
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发表时间：
1982
影响因子：
4.2
通讯作者：
T. Tolliver
中科院分区：
文献类型：
--
作者：
J. G. Bieri;T. Tolliver
：本研究探讨了膳食视黄酸可能导致先前描述的α-生育酚肠道吸收减少的几种可能机制。对大鼠粪便排泄的测量表明，饮食中的视黄酸引起的α-生育酚排泄量是视黄醇作为维生素A来源时的两倍。游离和酯化的α-生育酚的排泄量相同，因此，最初观察到的视黄酸效应并不是由于酯的水解受损所致。视黄酸对甘油三酯的吸收没有影响。对喂食两种维生素 A 的大鼠的胆汁进行收集和分析，结果显示胆汁体积或胆汁酸成分没有差异。然而，在饮食中添加 0.2% 牛磺胆酸则逆转了视黄酸对生育酚吸收的影响。含有 3H-α-生育酚和视黄酸或视黄醇的混合胶束的体外研究表明，由于胶束中维生素 A 的形式不同，其大小没有差异。
: This study explores several possible mechanisms by which dietary retinoic acid may cause the previously described reduced intestinal absorption of alpha-tocopherol. Measurement of fecal excretion of rats showed that dietary retinoic acid caused twice as much alpha-tocopherol to be excreted as when retinol was the source of vitamin A. Excretion was the same for free and esterified alpha-tocopherol, thus, the retinoic acid effect originally observed was not due to impaired hydrolysis of the ester. There was no effect of retinoic acid on triglyceride absorption. Collection and analysis of bile from rats fed either form of vitamin A showed no difference in bile volume or bile acid composition. The addition of 0.2% taurocholic acid to the diet, however, reversed the effect of retinoic acid on tocopherol absorption. In vitro studies of mixed micelles containing 3H-alpha-tocopherol and retinoic acid or retinol showed no difference in size due to the form of vitamin A in the micelles.