NEURAL METABOLISM AND NEUROTOXICOLOGY

神经代谢和神经毒理学

• 批准号: 2155218
• 负责人: HERBERT E LOWNDES
• 金额: $ 21.87万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 1997-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2155218
• 关键词: SDS polyacrylamide gel electrophoresis; acrylamides; brain cell; cerebellum; cytochrome P450; densitometry; dorsal root; electron microscopy; enzyme activity; enzyme induction /repression; enzyme inhibitors; gender difference; gene expression; glutathione transferase; high performance liquid chromatography; immunocytochemistry; in situ hybridization; laboratory mouse; laboratory rat; methylene chloride; neurotoxins; northern blottings; polymerase chain reaction; toxin metabolism; western blottings

The overall goal of this research program is to establish the relationship between expression of xenobiotic metabolizing enzymes, xenobiotic metabolism, and neurotoxicity. The neurotoxicity of many xenobiotics is characterized by remarkably specific involvement of particular cell types (pathoclisis) which may reflect unique differences in xenobiotic metabolism in targeted cells. The hypothesis of the proposed research is that regulation of expression of phase I and phase II enzymes in the nervous system is cell specific and this heterogeneity forms the basis for selective vulnerability of cells to some neurotoxicants. Preliminary data using immunocytochemistry and RT-PCR analysis show that CYP2E1, and class alpha, mu, and pi glutathione S-transferase (GST) expression is cell- specific in neural tissues. The proposed experiments will focus on the cerebellum and dorsal root ganglia (DRG) since certain cell types in these tissues exhibit selective vulnerability to experimental and therapeutic neurotoxicants. Gender and species differences in susceptibility to neurotoxicants will be exploited to determine relative contributions of the metabolic enzymes to neurotoxic outcome. Since little information is presently available regarding distribution of drug metabolizing enzymes in the nervous system, systematic characterization of the distribution of the enzymes and their responses to known inducers is required prior to testing the hypothesis using selected neurotoxic agents. Thus, the specific objectives of this research are addressed by the following questions: 1. Are there cell-specific patterns in the distribution of the xenobiotic metabolizing enzymes in cerebellum and DRG (which predispose discrete cellular populations to neurotoxicity)? 2. Are drug metabolizing enzymes in the brain inducible by xenobiotics and if so, is the induction cell-specific? 3. Does the cellular distribution of xenobiotic metabolizing enzymes determine and influence the cells response to neurotoxic chemicals? The relationships will be examined in two pathoclitic models of neurotoxicity; a. Acrylamide neurotoxicity in cerebellum and DRG. b. Methyl chloride neurotoxicity to cerebellar granule cells. These objectives will be approached using a variety of contemporary methodologies capable of detecting the distribution and expression of phase I and II enzymes in vivo and in vitro. The data resulting from these studies will provide a foundation for future mechanistic studies in which manipulation of enzyme level or activity, alone or in combination with other approaches, may be employed to determine the basis of neurotoxicity.

该研究计划的总体目标是建立关系 在异生物代谢酶的表达之间，异种生物 代谢和神经毒性。许多异种生物的神经毒性是 以特定的特定细胞类型的特定参与为特征 （病原体）可能反映异种生物的独特差异 目标细胞中的代谢。拟议研究的假设是 I期和II期酶在 神经系统特定于细胞，这种异质性构成了 细胞对某些神经毒性的选择性脆弱性。初步数据 使用免疫细胞化学和RT-PCR分析表明，CYP2E1和类 alpha，Mu和Pi谷胱甘肽S-转移酶（GST）表达是细胞 特异性在神经组织中。提出的实验将重点放在 小脑和背根神经节（DRG），因为其中某些细胞类型 组织表现出对实验和治疗的选择性脆弱性 神经毒性。 性别和物种的敏感性差异 神经毒性将被利用以确定 代谢酶促成神经毒性结果。因为很少的信息是 目前可用于药物代谢酶分布 神经系统，系统表征的分布 在测试之前，需要酶及其对已知诱导剂的反应 使用选定的神经毒性剂的假设。因此，具体 这项研究的目标是通过以下问题解决的： 1。在异种生物的分布中是否存在细胞特异性模式 小脑和DRG中的代谢酶（易感性离散 细胞种群具有神经毒性）？ 2。是异种生物诱导的大脑中的药物代谢酶， 如果是这样，感应细胞特异性是吗？ 3。异生物代谢酶的细胞分布是否存在 确定并影响细胞对神经毒性化学物质的反应？ 这 关系将在神经毒性的两个病原体模型中进行检查。 一个。小脑和DRG中的丙烯酰胺神经毒性。 b。 甲基氯化物神经毒性对小脑颗粒细胞。 这些目标将使用各种当代 能够检测的方法论 I阶段和II酶在体内和体外。这些产生的数据 研究将为未来的机械研究提供基础 单独或与之结合的酶水平或活性操纵 可以采用其他方法来确定神经毒性的基础。