γ-Tocotrienol, a vitamin E homolog, is a natriuretic hormone precursor
γ-Tocotrienol, a vitamin E homolog, is a natriuretic hormone precursor
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DOI：
10.1194/jlr.m300061-jlr200
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发表时间：
2003-08-01
影响因子：
6.5
通讯作者：
Igarashi, O
中科院分区：
文献类型：
--
作者：
Saito, H;Kiyose, C;Igarashi, O
2，7，8-Trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman是生育酚和生育三烯醇的代谢产物，是一种新的内源性利钠因子。然而，伽马-生育酚和伽马-生育三烯酚都是伽马-CEHC的前体，从未被直接观察到具有利钠效力。因此，我们调查了生育三烯醇是否会导致大鼠的利钠和利尿。这些大鼠被分成两组，分别给予对照组或高钠饮食4周，然后再分为安慰剂组和γ-生育三烯醇组，分别只给予去除玉米油的维生素E和添加了γ-生育三烯醇的油。大鼠口服三种实验剂量后，收集尿液，测定尿量、尿量、钠、钾含量。只有在给予高盐饮食的大鼠中，γ-生育三烯醇才能加速和增加钠的排泄，对钾的排泄没有影响。高盐组给予γ-生育三烯醇钠排泄量为5.06+/-2.70g/d，对照组给予γ-生育三烯醇钠排泄量为0.11+/-0.06g/d。此外，在高盐度体内储存和补充γ-生育三烯醇的特定条件下，γ-生育三烯醇会影响尿量。JLR在本研究中，我们发现天然维生素E同系物之一的γ-生育三烯醇能刺激体内钠的排泄，这表明伽马-生育三烯醇具有激素样利钠功能。
2,7,8-Trimethyl-2-(beta-carboxyethyl)-6-hydroxychroman (gamma-CEHC); a metabolite of gamma-tocopherol and gamma-tocotrienol, was identified as a new endogenous natriuretic factor. However, gamma-tocopherol and gamma-tocotrienol, both precursors of gamma-CEHC, have never directly been observed to have natriuretic potency. Thus, we investigated whether gamma-tocotrienol could cause natriuresis and diuresis in rats. The rats were divided into two groups that were given a control or a high-sodium diet for 4 weeks, and then subdivided into placebo and gamma-tocotrienol subgroups given only corn oil-removed vitamin E and oil supplemented with gamma-tocotrienol, respectively. After oral administration of three experimental doses, rat urine was collected and gamma-CEHC, urine volume, sodium, and potassium content were determined. Only in rats given a high-NaCl diet did gamma-tocotrienol accelerate and increase sodium excretion, showing no effect on potassium excretion. Sodium excretion in the high-NaCl group given gamma-tocotrienol was 5.06 +/- 2.70 g/day, and in the control group given gamma-tocotrienol, 0.11 +/- 0.06 g/day. Furthermore, gamma-tocotrienol affected urine volume in the specific condition of high-NaCl body stores and gamma-tocotrienol supplementation. jlr In this study, we found that gamma-tocotrienol, one of the natural vitamin E homologs, stimulates sodium excretion in vivo, suggesting that gamma-tocotrienol possesses a hormone-like natriuretic function.