HUMAN SELENIUM NUTRITIONAL REQUIREMENT AND BIOMARKERS

描述：人群的硒摄入量从严重缺乏到 在中国的一些地区，包括西藏，到委内瑞拉和其他地区的高 中国地区。美国和加拿大的摄入量似乎是足够的。 然而，许多其他国家，包括几乎所有的欧洲和 斯堪的纳维亚半岛，摄入量在推荐摄入量水平之间，仅为2 为确定硒的需要量而进行的研究。因此，有 不确定预防缺乏症等所需的硒含量 一个值对于决定是否补充符合以下条件的人口将是重要的 有接近要求的进水口。正在计划进行研究，以评估 通过给予药理剂量的硒来预防癌症。 需要硒的生物标记物来控制这些研究和监测 安全性和合规性。近年来，人们了解到了许多关于 硒代谢。有一种非特异性的代谢，涉及到硒 在硒蛋氨酸中，以及一种识别硒和 将其结合到特定的硒蛋白和其他代谢产物中。因此，一个 选择不同生物标志物研究硒充分性的合理依据 药理剂量的硒也是可用的。我们建议进行一项 中国低硒地区硒含量测定的研究 最大化血浆硒蛋白硒蛋白P和GSHPx-3所需 (生物标志物)。我们将与有长期经验的中国调查人员合作 在这样的工作中。这项研究将提供可用于计算 建议的膳食硒摄入量，可应用于 世界。我们建议进行第二项临床研究，以确定和描述 药理硒摄入量的生物标志物。它将评估3种形式的 并将为服用硒的研究人员提供指导 饮食要求以上的受试者。我们将为以下方面开发ELISA 硒蛋白P和GSHPx-3促进研究，我们将尝试 鉴定一种小分子形式的硒，A-Se，它似乎是一种 元素在等离子体中的传输形式。A-Se将作为生物标志物进行评估 用于人体的硒负荷和摄入量。这些研究都是为了改进 对人体内硒代谢的了解。他们还应该提供 为需要评估研究对象的硒缺乏症的研究人员提供的工具 以及药理剂量的硒的摄入量。

DESCRIPTION: The selenium intakes of populations vary from severely deficient in some regions of China, including Tibet, to high in Venezuela and in other regions of China. Intakes in the U.S. and Canada appear to be adequate. However, many other countries, including virtually all of Europe and Scandinavia, have intakes between the recommended intake levels of the only 2 studies carried out to determine the selenium requirement. Thus, there is uncertainty about the amount of selenium needed to prevent deficiency and such a value would be important for deciding on supplementation of populations that have intakes near the requirement. Studies are being planned to evaluate the prevention of cancer by administration of pharmacologic doses of selenium. Biomarkers of selenium are needed to control those studies and to monitor safety and compliance. In recent years a great deal has been learned about selenium metabolism. There is a non-specific metabolism, involving the selenium in selenomethionine, and a specific metabolism that recognizes selenium and incorporates it into specific selenoproteins and other metabolites. Thus, a rational basis for choosing separate biomarkers for studying selenium adequacy and pharmacologic amounts of selenium is available. We propose to carry out a study in a low-selenium area of China to determine the amount of selenium needed to maximize the plasma selenoproteins selenoprotein P and GSHPx-3 (biomarkers). We will work with Chinese investigators who have long experience in such work. The study will provide data that can be used for calculating a recommended dietary allowance of selenium that can be applied throughout the world. We propose a second clinical study to identify and characterize biomarkers for pharmacologic selenium intake. It will evaluate 3 forms of selenium and will provide guidance to investigators administering selenium of subjects above the dietary requirement. We will develop ELISAs for selenoprotein P and GSHPx-3 to facilitate the studies and we will attempt to identify a small-molecule form of selenium, A-Se, that appears to be a transport form of the element in plasma. A-Se will be evaluated as a biomarker for selenium body burden and intake. These studies are all designed to improve understanding of selenium metabolism in human beings. They should also provide tools for investigators who need to evaluate subjects for selenium deficiency and for intake of pharmacologic amounts of selenium.