Biosynthesis of retinoic acid by intestinal enzymes of the rat.
Biosynthesis of retinoic acid by intestinal enzymes of the rat.
复制标题
大鼠肠道酶生物合成视黄酸。
DOI：
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发表时间：
1967
影响因子：
6.5
通讯作者：
W. Virginia
中科院分区：
文献类型：
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作者：
F. Crain;F.;Lotspeich;Krause;W. Virginia
β-胡萝卜素-(14)C与肠粘膜的可溶性部分孵育，可形成少量酸性物质。在可溶部分中加入NAD或NADH可使该材料的含量增加10倍。将视网膜-15-(14)C与肠粘膜的可溶性部分加NAD或NADH孵育，可使80-90%的视网膜转化为酸性物质，已证明含有维甲酸。活体研究表明，在给予β-胡萝卜素-(14)C后，肠粘膜中维甲酸的形成可将相当数量的β-胡萝卜素转化为酸性化合物。当给予视网膜-15-(14)C时，门脉血中含有30-40%的吸收放射性。其中24%的放射性存在于酸性物质中，已被证明含有维甲酸。据推测，大鼠肠道中的酶将β-胡萝卜素裂解成视网膜，并将后者氧化成维甲酸，然后通过门静脉循环输送到肝脏。
The incubation of beta-carotene-(14)C with the soluble fraction of the intestinal mucosa resulted in the formation of small amounts of acidic material. The addition of NAD or NADH to the soluble fraction caused a tenfold increase in this material. Incubation of retinal-15-(14)C with the soluble fraction of the intestinal mucosa plus NAD or NADH resulted in the conversion of 80-90% of the retinal to acidic material, which has been shown to contain retinoic acid. In vivo studies on the formation of retinoic acid in the intestinal mucosa after the administration of beta-carotene-(14)C revealed that an appreciable amount of beta-carotene was converted to acidic compounds. When retinal-15-(14)C was administered, portal blood contained 30-40% of the absorbed radioactivity. 24% of this radioactivity was found in acidic material, which has been shown to contain retinoic acid. It is suggested that enzymes in rat intestine cleave beta-carotene to retinal and oxidize the latter to retinoic acid, which is then transported via the portal circulation to the liver.