DOPAMINE REGULATION IN THE SELECTIVE VULNERABILITY OF DOPAMINERGIC NEURONS

多巴胺能神经元选择性脆弱性的调节

• 批准号: 6243528
• 负责人: TERESA G HASTINGS
• 金额: $ 9.01万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-05-10 至 1998-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6243528
• 关键词: 6 hydroxydopamine; Parkinson's disease; SDS polyacrylamide gel electrophoresis; centrifugation; corpus striatum; dopamine; dopamine receptor; experimental brain lesion; immunocytochemistry; laboratory rat; neural degeneration; neurons; neurotoxins; neurotransmitter metabolism; oxidative stress; pathologic process; receptor binding; receptor sensitivity; substantia nigra

This project will focus on the role of reactive metabolites of dopamine (DA) in the process of neurodegeneration. We hypothesize that (a) the oxidation of DA to free radicals and reactive DA quinones results in the selective destruction of DA terminals, (b) this will occur with both exogenous and endogenous DA, and ' the selectivity is due to the presence of high levels of cytoplasmic DA within the terminal where oxidation occurs. We have shown in rats that an intrastriatal injection of DA results in the formation of DA oxidation products, proteins-bound cysteinyl- catechols, and show evidence of selective toxicity to DA terminals. In the proposed experiments, we will examine more thoroughly the phenomenon of DA-induced toxicity in the rat model using biochemical indices of DA oxidation and biochemical and immunohistochemical indices of toxicity. First, we will rigorously examine whether exogenous DA produces a selective loss DA terminals, and whether the loss of terminals results in the subsequent loss of DA cells in the substantia nigra. Secondly, we will examine the vulnerability of DA terminals to DA-induced toxicity under conditions more readily associated with the disease such as in the aged, antioxidant-deficient, or metabolically- impaired rat. In addition, we will examine the neurotoxic effects of chronically administered intrastriatal DA and induces of DA oxidation following increased availability of endogenous DA in the 6-OHDA-lesioned rat exposed to L-dOPA. Thirdly, we will examine the role of DA uptake and DA metabolism as the mechanism associated with the selective vulnerability of DA terminals to DA-induced oxidative stress. This group of studies will examine the role of DA as opposed to other oxidants, and the effect of blocking DA uptake or DA metabolism on the selective toxicity to DA terminals. Finally, we will begin to examine potential protein targets of DA quinone binding both intracellularly and extracellularly. Specific effects of extracellular reactive metabolites on DA receptor binding will be examined as part of this study. The results of these studies will help to clarify whether reactive metabolites of DA may be contributing to the pathogenesis associated with the loss of DA neurons in Parkinson's disease as well as identify potentially useful therapeutic interventions.

该项目将重点介绍反应性代谢物的作用 在神经退行性过程中多巴胺（DA）。 我们 假设（a）DA对自由基的氧化和 反应性DA Quinones导致DA的选择性破坏 末端，（b）这将发生在外源和内源性的情况下发生 da，'选择性是由于高水平的存在 发生氧化的末端内的细胞质DA。 我们 在大鼠中表明，纹状体内注射DA会导致 DA氧化产物的形成，结合蛋白质的半胱氨酸 - 儿茶酚，并显示出对DA的选择性毒性的证据 终端。 在拟议的实验中，我们将检查更多 彻底彻底的DA诱导的毒性现象 使用DA氧化和生化的生化指标的模型 和免疫组织化学指标。 首先，我们会的 严格检查外源性DA是否产生选择性 损失DA终端以及终端损失是否导致 随后在黑质中丢失了DA细胞。 其次，我们 将检查DA终端对DA诱导的脆弱性 条件下与该疾病更容易相关的毒性 例如在老化的，抗氧化剂缺陷或代谢中 大鼠受损。 此外，我们将检查神经毒性作用 长期给药的纹状体内DA和DA的诱导 氧化增加了内源性DA的可用性后 暴露于l-dopa的6- OHDA渗透的大鼠。 第三，我们会的 研究DA摄取和DA代谢的作用 与DA的选择性脆弱性相关的机制 末端到DA诱导的氧化应激。这一研究 将检查DA而不是其他氧化剂的作用，以及 阻止DA摄取或DA代谢对选择性的影响 对DA终端的毒性。 最后，我们将开始检查 da喹酮结合的潜在蛋白质靶标两种细胞内结合 和细胞外。 细胞外反应的特定作用 DA受体结合上的代谢产物将作为一部分检查 这项研究。 这些研究的结果将有助于澄清 DA的反应性代谢物是否可能有助于 与DA神经元丧失有关的发病机理 帕金森氏病，并确定潜在有用的 治疗干预措施。