NEURAL METABOLISM AND NEUROTOXICOLOGY

神经代谢和神经毒理学

• 批准号: 2155220
• 负责人: HERBERT E LOWNDES
• 金额: $ 21.73万
• 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 1998-10-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2155220
• 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; neurotoxicology; 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.

本研究计划的总体目标是建立 异生物质代谢酶、异生物质 代谢和神经毒性。许多异生物质的神经毒性是 以特殊细胞类型的显著特异性参与为特征 （pathoclisis）这可能反映了异生素的独特差异 在靶细胞中的代谢。拟议研究的假设是 调节I相和II相酶在细胞中的表达， 神经系统是细胞特异性的，这种异质性形成了神经系统的基础。 细胞对某些神经毒物的选择性脆弱性。初步数据 免疫细胞化学和RT-PCR分析表明，CYP 2 E1和类 α、μ和π谷胱甘肽S-转移酶（GST）的表达是细胞内的。 在神经组织中有特异性。拟议的实验将侧重于 小脑和背根神经节（DRG），因为这些神经节中的某些细胞类型 组织表现出对实验性和治疗性的选择性脆弱性， 神经毒剂 易感性的性别和物种差异 神经毒物将被用来确定相对贡献 代谢酶导致神经毒性结果。由于信息不多， 目前可获得的关于药物代谢酶在 神经系统，系统表征的分布， 酶及其对已知诱导剂的反应 使用选定的神经毒剂的假设。因此，具体 本研究的目标是通过以下问题解决： 1.异生物质的分布是否有细胞特异性 小脑和DRG中的代谢酶（其使离散的 细胞群神经毒性）？ 2.大脑中的药物代谢酶是否可由外源性物质诱导， 如果是，诱导是否具有细胞特异性？ 3.异生物质代谢酶的细胞分布 决定和影响细胞对神经毒性化学物质的反应？ 的 将在两种神经毒性的病理性模型中检查关系; a.丙烯酰胺对小脑和背根神经节的神经毒性。 B. 氯甲烷对小脑颗粒细胞的神经毒性。 这些目标将采用各种当代 能够检测的分布和表达的方法 体内和体外I相和II相酶。由此产生的数据 研究将为未来的机制研究提供基础， 酶水平或活性的操纵，单独或与 可以采用其他方法来确定神经毒性的基础。