METAL SPECIATION--EFFECT ON TRANSPORT AND INTERACTIVE TOXICITY

金属形态——对运输的影响和相互作用的毒性

• 批准号: 3755183
• 负责人: DEAN E CARTER
• 金额: --
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3755183
• 关键词: affinity chromatography; albumins; atomic absorption spectrometry; biomarker; body fluids; cadmium; cations; cell population study; cell type; clone cells; cysteine; cytotoxicity; dogs; erythrocyte membrane; erythrocytes; glutathione; heavy metals; ion transport; kidney cell; laboratory rabbit; laboratory rat; ligands; liver cells; mercury; metal complex; metal poisoning; metallothionein; oxidation; tissue /cell culture; toxicant interaction; zinc

It is generally recognized that metal ions do not circulate freely in biological fluids, but are bound to endogenous ligands (e.g., proteins, amino acids, etc.) in blood and cells. The metal ion may be the ultimate toxin but the dose-response relationship and/or the access into the cell is undoubtedly controlled by the form of the metal in the blood or bathing medium. The goal of this project is to establish a relationship between metal transport and metal toxicity using the chemical species that occur in blood. The hypotheses of this project are as follows: I. In the systemic circulation, metals will exist primarily as metal complexes with endogenous ligands and not as the free ions. II. The rate of metal uptake and the extent of toxicity in in vitro systems is dependent on the actual metal species which are found in blood. This project will focus on thiol binding ligands (cysteine, glutathione, albumin, metallothionein) and will examine the effect of metal complexes on cellular transport and toxicity. Metal ions which will be examined belong to Group IIB of the Periodic Table: Cd(II), Hg(II), and Zn(II). The specific aims include the following: 1). Determine an internally consistent set of values for the metal-ligand formation constants, ligand concentrations in various body compartments (including blood, extra- and intracellular fluids), and total metal concentrations found in various body compartments. Use solution equilibria calculations found on standard computer programs to predict the most prevalent metal species that should be found in the various body compartments. 2). Metal-Protein exchange reactions will be studied using recently developed chromatographic techniques. The thermodynamics, and possibly the kinetics, of the exchange reaction can be determined by the elution and/or location of the metal ion as a function of time. 3). Examine the uptake and toxicity of the metal ion complexes by using in vitro preparations of isolated cell populations in culture. The cell populations will include erythrocytes and erythrocyte ghosts; LLC-PK1 kidney cells and primary proximal kidney tubule preparations; and ARL-18 (liver) epithelial cells and primary liver hepatocyte preparations.

一般认为，金属离子不能在空气中自由循环。 生物流体，但与内源性配体结合（例如，蛋白质， 氨基酸等）在血液和细胞中。 金属离子可能是 毒素，但剂量-反应关系和/或进入细胞的途径， 毫无疑问是由血液或洗澡中的金属形式控制的 介质 这个项目的目标是建立一个关系， 金属运输和金属毒性使用的化学物种发生在 血 本课题的研究假设如下：一、研究方法。的全身 循环中，金属将主要以金属络合物的形式存在， 配体而不是自由离子。 二.金属吸收率和 体外系统中的毒性程度取决于实际金属 在血液中发现的物种。 这个项目将集中在巯基结合 配体（半胱氨酸，谷胱甘肽，白蛋白，金属硫蛋白），并将检查 金属配合物对细胞转运和毒性的影响。 金属 将被检查的离子属于周期表的IIB族： Cd（II）、Hg（II）和Zn（II）。 具体目标包括：1）。 确定金属配体的一组内部一致的值 形成常数，各种身体隔室中的配体浓度 （包括血液、细胞外液和细胞内液）和总金属 在不同的身体隔间中发现的浓度。 使用溶液平衡 在标准计算机程序中发现的计算， 普遍存在的金属物种，应在各种机构 隔间 2）。金属-蛋白质交换反应将使用 最近开发的色谱技术。 热力学，以及 可能地，交换反应的动力学可以通过 作为时间的函数的金属离子的洗脱和/或位置。 3）。 通过使用中，检查金属离子络合物的摄取和毒性。 培养物中分离的细胞群的体外制备。 细胞 群体将包括红细胞和红细胞血影; LLC-PK 1 肾细胞和原代近端肾小管制备物;和ARL-18 （肝）上皮细胞和原代肝细胞制备物。