PROCESSES OF METAL SELECTION BY METAL ACCUMULATING CELLS

本项目的目的是确定和描述 使海洋中的毛孔细胞 原支腹足类Littorina littorea 优先积累铜，而不是其他生物可利用的金属。一个 已经设计了一系列实验来证明 这些细胞从血液中积累金属，并测试是否 细胞在体内表现出的选择性是由于：(1) 此特定细胞类型所特有的固有属性；(2) 其他细胞类型的活动，如嗜碱性细胞 从血液中除去铜以外的金属；(3)体液 与铜结合并同时起作用的因素将金属引导到 细胞并促进其摄取。许多技术包括 细胞培养、能量色散X射线微区分析、辐射计量学 分析、凝胶电泳、尺寸排除高效 高效液相色谱与电感耦合等离子体质谱 光谱分析将被用来解决 上述三个因素。短期动力学研究将 也可以用来确定细胞对铜的吸收是否 承运人调停。竞争性抑制研究与其他 金属将被用来确定摄取的特异性 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……里面 结合起来，这些研究将提供一种机械性的 理解允许顺序操作的流程 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 也有助于铜基杀螺剂的开发以控制 血吸虫病的腹足类生物寄生传播 光肩星。最后，这些研究是第一次尝试 对细胞内铜的通量和周转进行定量研究 电感耦合等离子体稳定同位素分析~(63)Cu 质谱学。因此，这种技术提供了一种新的 与健康相关的科学研究的方法论 必需的，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.