ETHANOL AND GLUTATHIONE ON NMDA RECEPTOR FUNCTION

乙醇和谷胱甘肽对 NMDA 受体功能的影响

• 批准号: 2045564
• 负责人: STEVEN W LESLIE
• 金额: $ 14.27万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-01 至 1997-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2045564
• 关键词: NMDA receptors; alcoholism /alcohol abuse; brain metabolism; calcium channel; cell membrane; cerebellum; cerebral cortex; corpus striatum; drug interactions; embryo /fetus toxicology; ethanol; fetal alcohol syndrome; glia; glutathione; growth /development; hippocampus; laboratory rat; mature animal; medulla oblongata; newborn animals; pons; pregnancy; receptor binding; tissue /cell culture

The NMDA-stimulated glutamate receptor Subtype in the brain appears to be involved in many important neuronal processes such as neuronal development, neuronal toxicity and learning and memory. Studies in our and other laboratories have shown that NMDA-receptor mediated processes in the brain are highly sensitive to inhibition by ethanol. Recent work in my laboratories has shown that glutathione (gamma-glutamylcysteinylglycine) stimulates NMDA receptors in an apparent competitive manner to enhance calcium entry through NMDA-stimulated ion channels. Glutathione is found in high concentrations in the brain, particularly high in glial cells. Recent work has shown that glutathione is released from glial cells in a robust manner. Taken together with recent results from my laboratories, the evidence suggests that glutathione (released from glial cells) may activate and possibly regulate NMDA receptor function. The overall objective of the proposed research will be to characterize the interactions of glutathione on NMDA receptor function and to determine the influence of acute and chronic alcohol exposure and prenatal ethanol exposure on the synthesis and release of glutathione and to study the influence of acute and chronic ethanol and prenatal ethanol exposure on glutathione interactions with NMDA receptors. Initially, studies will be conducted to characterize the effects of acute and chronic ethanol and fetal ethanol exposure on the brain concentrations and turnover of reduced (GSH) and oxidized (GSSG) glutathione. Brain regions to be studied will be those with high (cerebellum, cerebral cortex, hippocampus), intermediate (striatum) and low (pons-medulla) densities of NMDA-receptors. Studies are also designed to determine the effects of ethanol on the interactions of glutathione (GSH and GSSG) added in vitro on calcium entry through NMDA-stimulated channels in dissociated neurons. Experiments will also be carried out to demonstrate the mechanistic effects of ethanol in which receptor binding studies will be conducted on membranes from newborn and adult brain regions. The effects of invitro ethanol (5 - 100 mM) and chronic ethanol and its interactions with glutathione will be Studied. Experiments will be conducted on the effects of ethanol and glutathione on the Kd and Bmax for 3H-CPP (NMDA competitive site), 3H-glycine (co-agonist site), and H-MK-801 (allosteric, channel inhibitory PCP site) binding. Finally, studies are designed to characterize the effects of chronic ethanol administration to pregnant, female rats on the glutathione/NMDA-receptor interactions in dissociated neurons from newborn rat pups. These studies will address the question of the possible role that glutamate containing peptides may play in fetal abnormalities after maternal ethanol exposure.

NMDA刺激的大脑中的谷氨酸受体亚型似乎是 参与许多重要的神经元过程，例如神经元发展， 神经元毒性，学习和记忆。 我们和其他 实验室已经表明NMDA受体介导的大脑过程 对乙醇的抑制高度敏感。 我最近的工作 实验室表明谷胱甘肽（γ-谷氨酰囊酯甘氨酸） 以明显的竞争方式刺激NMDA受体以增强 通过NMDA刺激的离子通道进入钙。 发现谷胱甘肽 在大脑的高浓度中，尤其是神经胶质细胞中的高浓度。 最近的工作表明，谷胱甘肽是从A中的神经胶质细胞中释放的 坚固的方式。 结合了我的实验室的最新结果， 证据表明谷胱甘肽（从神经胶质细胞中释放）可能 激活并可能调节NMDA受体功能。 总体 拟议研究的目的是表征相互作用 谷胱甘肽对NMDA受体功能的作用，并确定 急性和慢性酒精暴露以及产前乙醇暴露于 谷胱甘肽的合成和释放并研究急性的影响 以及谷胱甘肽的慢性乙醇和产前乙醇暴露 与NMDA受体的相互作用。 最初，将进行研究 表征急性和慢性乙醇和胎儿乙醇的影响 暴露于脑浓度和减少（GSH）和周转的情况下（GSH）和 氧化（GSSG）谷胱甘肽。 要研究的大脑区域将是 具有高（小脑，脑皮质，海马），中级 NMDA受体的（纹状体）和低（PONS-MEDULLA）密度。 研究是 还旨在确定乙醇对 谷胱甘肽（GSH和GSSG）在体外通过钙进入，通过 NMDA刺激的神经元中的通道。 实验也将是 进行以证明乙醇的机械作用 受体结合研究将在新生儿的膜上进行 成人大脑区域。 Invitro乙醇（5-100毫米）和 将研究慢性乙醇及其与谷胱甘肽的相互作用。 实验将对乙醇和谷胱甘肽的影响进行实验 3H-CPP（NMDA竞争地点），3H-甘氨酸（共同激动剂）的KD和BMAX 位点）和H-MK-801（变构，通道抑制性PCP位点）结合。 最后，研究旨在表征慢性的影响 乙醇给怀孕的雌性大鼠 新生儿解离神经元中的谷胱甘肽/NMDA受体相互作用 大鼠幼崽。 这些研究将解决可能角色的问题 含有谷氨酸的肽可能会在胎儿异常中起作用 母体乙醇暴露。