INTESTINAL ENDOGENOUS ZINC: ROLE FOR METALLOTHIONEIN

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。锌（Zn）缺乏症已在全球范围内得到充分证明，锌缺乏症对健康的不利影响也是如此。锌在人体中有许多重要的功能，但锌的确切使用方式仍有待研究。健康的人通过调节从食物中吸收锌进入肠道，并通过控制锌释放回肠道以通过粪便排出，来平衡体内锌的含量。大多数研究都集中在肠道对锌的吸收上。本研究将更好地描述锌进入肠道的生理和影响因素。提高对身体通常达到适当锌平衡的方式的理解可能有助于最终治疗和/或预防锌缺乏症。这项研究将调查一种蛋白质，金属硫蛋白，是否控制锌分泌进入肠道。根据动物实验数据和我们自己的初步数据，我们假设胰腺进入小肠分泌物中金属硫蛋白的含量与这些分泌物中锌的含量直接相关。本研究还将评估胰腺分泌物中金属硫蛋白的含量是否会随着食物中锌的吸收量和体内锌负荷的变化而变化。年龄在20-50岁之间的健康成年人将从丹佛市区招募。我们将对10名受试者进行研究，他们的饮食中锌的含量与他们平时的饮食相似。然后，受试者将被随机分配到锌限制或补充饮食中。在开始指定饮食之前和之后，受试者将在GCRC中度过2天，在此期间，将一根小管插入每位受试者的口腔并沿着喉咙进入肠道。这个管子将被用来吸出分泌物，然后我们将进行分析。所有受试者在研究期间的不同时间也会接受一些特殊形式的锌。这将帮助我们测量收集的分泌物中的锌含量

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Zinc (Zn) deficiency has been amply demonstrated on a global basis, as have the adverse implications of Zn deficiency on health. Zn has many important functions in the body, and yet much remains to be learned about exactly how Zn is used. Healthy individuals balance the amount of Zn in their bodies by regulating absorption of Zn from food into the gut and by controlling the release of zinc back into the intestine for excretion in feces. Most research has focused on zinc absorption by the gut. This study will better characterize the physiology of and factors affecting zinc secretion into the intestine. An improved understanding of the ways in which the body usually achieves proper zinc balance may help to ultimately treat and/or prevent Zn deficiency. This study will investigate if a protein, metallothionein, controls Zn secretion into the intestine. Based on experimental data from animal studies and our own preliminary data, we hypothesize that the amount of metallothionein in secretions from the pancreas into the small intestine is directly related to the amount of Zn in these secretions. This study will also evaluate whether the amount of metallothionein in secretions from the pancreas changes when the amount of zinc absorbed from food changes and when the Zn load in the body changes. Healthy adults aged 20-50 will be recruited from the Denver metro area. We will study 10 subjects on a diet with Zn levels similar to their usual diets. Subjects will then be randomly assigned to a Zn restricted or supplemented diet. Before and after they begin their assigned diet, subjects will spend 2 days in the GCRC, where a small tube will be inserted into each subject's mouth and advanced down his/her throat to his/her intestine. This tube will be used to suck out secretions that we will then analyze. All subjects will also receive some special forms of Zn on different days in the study. These will help us to measure Zn amounts in the secretions collecte