ABSORPTION/TURNOVER/BIOCHEMISTRY--ZINC NUTRITION

锌对人体健康是必不可少的。边际缺锌 似乎很普遍，但对此的诊断标准有 没有被开发出来。的动态平衡控制机制 锌缺乏和锌充足状态下的胃肠道水平 并不能很好地表现在人类受试者身上。具体目标 这个项目的目的是定义边缘锌缺乏症 受试者，并确定动态平衡控制机制 锌。这些目标将通过实验来实现。 在成年志愿者中诱导轻微的特异性锌缺乏 之后是适当的再补充阶段。的参数 测量将测量：锌的吸收率，a 用新方法测量流动人体锌库 稳定同位素(电感耦合等离子体质谱 (电感耦合等离子体质谱)、锌平衡、血浆锌浓度、红细胞、 中性粒细胞、淋巴细胞和唾液中锌的测定 血浆、红细胞、淋巴细胞和 中性粒细胞、暗适应、血清激素和淋巴细胞 功能测试。一种以组织化大豆为基础的半纯饲料 我们将使用不同锌水平的蛋白质进行研究。 所有其他宏观和微观营养素将按照 RDA。在整个实验过程中，饮食将保持不变 除锌外(3毫克/天在锌耗竭阶段，30 在锌补充阶段，每天增加1毫克)。碱性磷酸酶在细胞中的作用 血浆、核苷磷酸酶和Delata氨基乙酰丙酸 红细胞中的脱水酶，碱性磷酸酶中的 中性粒细胞(定量)、核苷磷酸化酶和ECTO 淋巴细胞中的5‘核苷酸酶，将被测定并 与饮食引起的锌水平变化相关 操纵。淋巴细胞功能的体外检测 活性(NK细胞、IL-1和IL-2产生)、表面标志和 还将进行细胞培养研究。在耗尽期间- 锌的贫化阶段，适当的胃液测量。 肠道吸收、锌平衡与内源性粪便丢失 秘密的锌将会被执行。因此，这些研究将 为我们提供敏感的诊断标准 边际缺锌，并将提供体内平衡控制 锌在胃肠水平的作用机制。尝试将 研制抗金属硫蛋白的单抗 杂交瘤技术及其ELSA检测技术的建立 在研究过程中血浆中的蛋白质。锌的肠道分泌功能 是由孵化研究确定的。

Zinc is essential for human health. Marginal deficiency of zinc appears to be widespread but the diagnostic criteria for this have not been developed. Homeostatic control mechanisms at the gast-intestinal tract level during zinc deficiency and sufficiency are not well characterised in human subjects. The specific aims of this project are to define marginal zinc deficiency inhuman subjects and to determine homeostatic control mechanisms of zinc. These objectives will be accomplished by experimentally inducing a marginal specific deficiency of zinc in adult volunteers followed by appropriate repletion phases. The parameters of measurement of measurement will be: zince absorption, a measurement of mobile body zinc pool by using the novel method of stable isotopes (Inductively Coupled Plasma Mass Spectrometry (ICP/MS)), zinc balance, zinc concentration in plasma, red cells, neutrophils, lymphocytes, and saliva, assay of selected zinc- dependent enzymes in the plasma, red cells, lymphocytes, and neutrophils, dark adaptation, serum hormones, and lymphocyte funciton tests. A semi-purified diet based on texturized soy protein with different levels of zinc will be used for our study. All other macro and micro-nutrients will be supplied according to RDA. Throughout the experiment, the diet will remain constant except for zinc (3 mg/day during zinc-depletion phase and 30 mg/day during zinc-repletion phase). Alkaline phosphatease in the plasma, nucleoside phospyorylase and delata amino levulinic acid dehydratase in the red cells, alkaline phosphatase in the neutrophils (quantitative), and nucleoside phosphorylase and ecto 5' nucleotidase in the lymphocytes, will be determined and correlated with changes in zinc levels due to dietary manipulation. In vitro assessments of lymphocytefunctional activity (NK cell, IL-1, and IL-2 prodcution), surface markers, and cell culture studies will also be made. During the depletion- epletion phases for zinc, apprpriate measurements of gastro- intestinal absorption, zinc balance, and fecal loss of endogenously secreted zince will be carried out. Thus, these studies will provide us with sensitive criteria for making a diagnosis of marginal zinc deficiency and will provide homeostatic control mechanism of zinc at the gastro-intestinal level. Attempts will be made to develop monoclonal antibody to metallothioein by Hybridoma technique and set up ELSA technique for assay of this protein in plasma during the study. Intestinal secrtion of zinc will be determine by incubation studies.