TARGET SITES AND COMPARTMENTALIZATION IN HEAVY METAL EXPOSED CELLS

重金属暴露细胞的靶位点和区室化

• 批准号: 3756174
• 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/3756174
• 关键词: Chlorophyta; Saccharomyces; X ray microscopy; alternatives to animals in research; atomic absorption spectrometry; cadmium; cell membrane; copper; electron microscopy; freeze etching; intracellular; lead; membrane structure; mercury; metal poisoning; minority institution research support; organelles; plant growth regulators; tissue /cell culture; transmission electron microscopy; 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 fractions 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 effects on cells. Work to date on Chlorella vulgaris indicates that 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.

本研究的目的是调查 重金属区室化试验细胞，并确定选择 金属离子对细胞膜结构和细胞器的特殊作用 分布 研究将在选定的剂量水平下进行， 常规的透射电子显微镜来确定细胞是否 发生了损害。 酿酒酵母和小球藻 普通人将暴露在不同浓度的五种环境- 显著重金属（Cd、Cu、Hg、Pb和Zn），以确定EC 50 暴露在金属中的细胞 然后将确定以下内容： (1)通过大小分析质膜改变的程度， 基本粒子（蛋白质）的形状、数量和分布 在冷冻断裂制备中，（2）特别是重金属位置 使用能量色散X射线空气微分析的细胞室， 干燥和/或冷冻切片的标本，（3）细胞结构， 通过施用重金属浓度改变， 随机取向的薄切片细胞的形态测定分析，以及（4）如果 任何通过原子吸收定位重金属的地方 用分光光度法测定由破碎细胞制备的级分。 从这些研究的结果来看，预计我们将获得 了解重金属如何对细胞造成某些有害影响。 迄今为止对小球藻的研究表明，膜颗粒可能是 改变镉以及某些其他细胞器和夹杂物。 这一信息应适用于重金属的影响，在所有 细胞水平包括人体影响。