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，在委内瑞拉和其他 中国的地区。在美国和加拿大的收入似乎是足够的。 然而，许多其他国家，包括几乎整个欧洲和 斯堪的纳维亚半岛，有摄入量之间的建议摄入量水平的唯一2 进行研究，以确定硒的需求。因此， 不确定硒的数量需要防止缺乏等 一个值对于决定补充人群很重要， 有接近要求的摄入量。目前正在计划进行研究， 通过服用药理学剂量的硒来预防癌症。 需要硒的生物标志物来控制这些研究和监测 安全性和合规性。近年来，人们已经了解了很多关于 硒代谢有一种非特异性代谢，涉及硒 在硒代甲硫氨酸，和一个特定的代谢，认识硒， 将其整合到特定的硒蛋白和其他代谢物中。因此 选择不同生物标志物研究硒充足性的合理依据 并且可获得药理学量的硒。我们建议进行一项 我国低硒地区硒含量测定研究 需要最大化血浆硒蛋白硒蛋白P和GSHPx-3 （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。该研究将提供可用于计算 推荐的硒的膳食允许量，可以应用于整个 世界我们建议进行第二项临床研究， 药理学硒摄入量的生物标志物。它将评估三种形式的 硒，并将为研究者提供指导， 超出饮食要求的受试者。我们将开发ELISA， 硒蛋白P和GSHPx-3，以促进研究，我们将试图 确定了一种小分子形式的硒，A-Se，似乎是一种 元素在等离子体中的运输形式。A-Se将作为生物标志物进行评价 硒的身体负担和摄入量。这些研究都是为了改善 了解硒在人体内的代谢。他们还应该提供 为需要评估受试者是否缺硒的研究者提供的工具 以及摄入药理学量的硒。

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.