Preferential organ distribution of methylselenol source Se-methylselenocysteine relative to methylseleninic acid.
Preferential organ distribution of methylselenol source Se-methylselenocysteine relative to methylseleninic acid.
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DOI：
10.1016/j.taap.2007.10.001
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发表时间：
2008-02
影响因子：
3.8
通讯作者：
Kazuo T. Suzuki;Y. Tsuji;Y. Ohta;N. Suzuki
中科院分区：
文献类型：
--
作者：
Kazuo T. Suzuki;Y. Tsuji;Y. Ohta;N. Suzuki
有人提出，硒甲基硒代半胱氨酸（MeSeCys）和甲基硒酸（MSAIV）分别通过β-裂合酶和还原反应有效转化为甲基硒醇，甲基硒醇是一种假定的生物活性硒代谢物，对硒的抗癌和抗氧化作用有反应。在完全相同的条件下比较了两种硒源在主要器官/组织中的生物利用度和分布。即，将标记的硒源 76Se-MeSeCys 和 77Se-MSAIV，分别以 10 μg Se/kg 体重的单次口服剂量，同时给予已用单一同位素 78 Se 耗尽天然丰度硒的大鼠。还施用相同剂量的 82 Se-亚硒酸盐作为参考硒源。给药 3 小时后，测定了三种标记的硒同位素在 13 个器官/组织/血液中的分布。 MeSeCys 比 MSAIV 和亚硒酸盐更有效地被大多数器官（特别是胰腺和十二指肠）吸收，后两种来源的吸收彼此相似，但在肾、肝和脾中除外，在肾、肝和脾中检测到三种标记同位素的浓度相当。通过 HPLC 电感耦合氩等离子体质谱 (ICP-MS) 对肝脏上清液中标记的硒进行形态分析，表明 MeSeCys 以完整形式递送至器官，然后转化为甲基硒醇。除了 MeSeCys 的已知特性之外，MeSeCys 的化学性质比 MSAIV 更稳定，并且是一种天然存在的可食用产品，并且 MeSeCys 比同源的硒代氨基酸硒代蛋氨酸更有效地产生甲基硒醇，本研究表明，MeSeCys 比完整形式的 MSAIV 更有效地分布，然后产生甲基硒醇，这表明 MeSeCys 是大多数情况下最好的甲基硒醇来源。器官/组织。
It has been proposed that Se-methylselenocysteine (MeSeCys) and methylseleninic acid (MSAIV) are efficiently transformed through the β-lyase and reduction reactions, respectively, into methylselenol, the assumed biologically active selenometabolite responsive for the anti-carcinogenicity and anti-oxidant actions of selenium. The bioavailability and distribution of the two selenium sources in major organs/tissues were compared under exactly identical conditions. Namely, labeled selenium sources76Se-MeSeCys and77Se-MSAIV, at a single oral dose of 10 μg Se/kg body weight each, were administered simultaneously to rats that had been depleted of natural abundance selenium with a single isotope78Se. The same dose of82Se-selenite was also administered as a reference selenium source. The distributions of the three labeled selenium isotopes were determined 3 h after the administration in 13 organs/tissues/blood. MeSeCys was taken up more efficiently by most organs, especially the pancreas and duodenum, than MSAIVand selenite, the latter two sources being taken up similarly to each other except for in the kidney, liver, and spleen, where the three labeled isotopes were detected at comparable concentrations. The labeled selenium in the liver supernatant was speciated by HPLC inductively coupled argon plasma-mass spectrometry (ICP-MS), and it was suggested that MeSeCys was delivered in its intact form to organs, and then transformed into methylselenol. In addition to the known properties of that MeSeCys is chemically more stable than MSAIVand is a naturally occurring edible product, and that MeSeCys produces methylselenol much more efficiently than a homologous selenoamino acid selenomethionine, the present study revealed that MeSeCys is more efficiently distributed than MSAIVin its intact form, and then produces methylselenol, suggesting that MeSeCys is the best methylselenol source in most organs/tissues.