PROCESSES OF METAL SELECTION BY METAL ACCUMULATING CELLS

该项目的目的是识别和表征 使海洋孔隙细胞能够发挥作用的机制 原鳃类腹足动物 Littorina littorea 特别是 优先于其他生物可利用金属积累铜。 一个 一系列的实验旨在证明 这些细胞从血液中积累金属并测试是否 观察到的体内细胞表现出的选择性是由于：(1) 这种特定细胞类型独有的内在特性； （2） 其他细胞类型的活性，例如嗜碱性粒细胞 从血液中去除铜以外的金属； (3)体液性 与 Cu 结合并作用于两者的因子将金属引导至 细胞并促进其吸收。 多项技术包括 细胞培养、能量色散X射线微量分析、辐射测定 分析、凝胶电泳、尺寸排阻高性能 液相色谱法和电感耦合等离子体质量 光谱测定法将用于解决以下问题的相对重要性 上述三个因素。 短期动力学研究将 还可以确定细胞对铜的吸收是否 载体介导。 与其他药物的竞争性抑制研究 金属将用于确定吸收的特异性 系统和运输系统的能量需求 还将使用各种代谢抑制剂进行研究。 在 结合起来，这些研究将提供一个机制 了解允许顺序的过程 金属的识别、选择和引导至特定细胞 高等真核生物中的类型。 从长远来看，这些研究将 还有助于开发基于铜的软体动物杀剂来控制 腹足动物传播血吸虫病 光滑。 最后，这些研究代表了首次尝试 使用以下方法定量研究细胞中铜的通量和周转 电感耦合等离子体对 63Cu 的稳定同位素分析 质谱分析。 因此，该技术提供了一种新的 研究此问题的健康相关科学方法 必需但具有潜在毒性的元素。

The purpose of this project is to identify and characterize the mechanisms which enable the pore cells of the marine prosobranch gastropod Littorina littorea to specifically accumulate Cu in preference to other bioavailable metals. A series of experiments have been designed to demonstrate that these cells accumulate metals from the blood and to test if the observed selectivity shown by the cells in vivo is due to: (1) intrinsic properties unique to this particular cell type; (2) the activities of other cell types such as the basophil cells in the removal of metals other than Cu from the blood; (3) humoral factors which bind to Cu and act to both vector the metal to the cell and facilitate its uptake. A number of techniques including cell culture, energy dispersive X-ray microanalysis, radiometric analysis, gel electrophoresis, size exclusion high performance liquid chromatography and inductively coupled plasma mass spectrometry will be used to resolve the relative importance of the three factors outlined above. Short term kinetic studies will also be undertaken to determine if Cu uptake by the cells is carrier mediated. Competitive inhibition studies with other metals will be used to determine the specificity of the uptake system and the energetic requirements of the transport system will also be studied using various metabolic inhibitors. In combination, these studies will provide a mechanistic understanding of the processes which permit the sequential recognition, selection and vectoring of metals to specific cell types in higher eukaryotes. In the long term, these studies will also help in the development of Cu based molluscicides to control the spread of schistosomiasis by the gastropod Biomphalaria glabrata. Finally, these studies represent the first attempt to study the flux and turnover of Cu in cells quantitatively using stable isotopic analysis of 63Cu by inductively coupled plasma mass spectrometry. This technique therefore offers a new methodology to the health related sciences for the study of this essential, but potentially toxic element.