CELLULAR TARGET SITES OF HEAVY METAL EXPOSED CELLS

重金属暴露细胞的细胞靶位点

• 批准号: 3916067
• 负责人: THOMAS E JENSEN
• 金额: --
• 依托单位: HERBERT H. LEHMAN COLLEGE
• 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/3916067
• 关键词: Chlorophyta; Saccharomyces; atomic absorption spectrometry; cadmium; copper; electron microscopy; heavy metals; lead; membrane structure; mercury; organelles; plant growth regulators; plant poisons; zinc

It is the purpose of the proposed research to investigate the degree of heavy metal compartmentalization in test cells and to determine selected specific effects of metal ions on membrane structure and organelle distribution. Studies are to be performed at selected dose levels with conventional transmission electron microscopy to determine if cellular damage has occurred. The organisms Saccharomyces cerevisiae and Chlorella vulgaris will be exposed to various concentrations of five environmentally- significant heavy metals (Cd, Cu, Hg, Pb and Zn) in order to determine EC50 of the cells exposed to the metals. The following will then be determined: (1) the degree of plasma membrane alteration by analyses on the size, shape, number and distribution of elementary particles (proteins) revealed in freeze-fracture preparation, (2) heavy metal location in particular cellular compartments using energy-dispersive X-ray microanalysis of air- dried and/or cryosectioned specimens, (3) cell structures which are most altered by the administration of heavy metal concentrations using morphometric analysis of randomly-oriented thin-sectioned cells, and (4) if any, where heavy metals are localized through the use of atomic absorption spectrophotometry on fraction prepared from disrupted cells. From the results of these studies it is anticipated that we should gain insights as to how heavy metals cause certain detrimental affects on cells. Work to date on Chlorella vulgaris indicates that analysis of membrane particles may be altered by Cd as well as certain other cell organelles and inclusions. This information should be applicable to heavy metal effects at all cellular levels including human effects. It has been found that in most cases cells from any source have a similar response. Thus the cellular data obtained here should be applicable to all cells within certain limits. Use of data from our system should provide data from which models of the cellular response to heavy metals can be obtained. This information can then be used in regard to whole animal response including humans to heavy metals as the damage is, of course, at the cellular level.

拟议研究的目的是调查 测试细胞中重金属的划分程度 确定金属离子对膜的特定影响 结构和细胞器分布。 待进行研究 在选定的剂量水平下使用传统的透射电子 显微镜检查以确定是否发生细胞损伤。 这 酿酒酵母 (Saccharomyces cerevisiae) 和小球藻 (Chlorella vulgaris) 生物体 暴露于不同浓度的五种环境- 重要的重金属（Cd、Cu、Hg、Pb 和 Zn），以便 确定暴露于金属的细胞的 EC50。 下列 然后将确定： (1) 质膜的程度 通过分析大小、形状、数量和分布来改变 冷冻断裂中揭示的基本粒子（蛋白质） 制备，（2）重金属在特定细胞中的定位 使用能量色散 X 射线微量分析空气的隔室 干燥和/或冷冻切片的标本，（3）细胞结构 受到重金属管理的影响最大 使用随机定向的形态计量分析来确定浓度 薄切片细胞，以及 (4) 如果有的话，其中含有重金属 通过使用原子吸收分光光度法进行定位 在从破碎的细胞制备的级分上。 从这些研究的结果来看，我们应该 深入了解重金属如何造成某些有害物质 对细胞的影响。 迄今为止对普通小球藻的研究表明 镉也可能改变膜颗粒的分析 作为某些其他细胞器和内含物。 此信息 应适用于所有细胞水平的重金属效应 包括人类的影响。 研究发现，在大多数情况下，任何来源的细胞都具有 类似的反应。 因此，这里获得的蜂窝数据应该是 适用于一定范围内的所有细胞。 使用来自 我们的系统应该提供来自哪些蜂窝模型的数据 可以获得对重金属的响应。 这些信息可以 然后用于包括人类在内的整个动物反应 当然，重金属的损害是在细胞水平上的。