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.

大脑中 NMDA 刺激的谷氨酸受体亚型似乎是 参与许多重要的神经元过程，例如神经元发育， 神经元毒性与学习和记忆。 我们和其他国家的研究 实验室表明 NMDA 受体介导大脑中的过程 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-谷氨酰半胱氨酰甘氨酸） 以明显的竞争性方式刺激 NMDA 受体以增强 钙通过 NMDA 刺激的离子通道进入。 发现谷胱甘肽 在大脑中浓度很高，特别是在神经胶质细胞中浓度很高。 最近的研究表明，谷胱甘肽是从神经胶质细胞中释放出来的。 稳健的方式。 结合我实验室的最新结果， 有证据表明谷胱甘肽（从神经胶质细胞释放）可能 激活并可能调节 NMDA 受体功能。 整体 拟议研究的目标是描述相互作用的特征 谷胱甘肽对 NMDA 受体功能的影响并确定 急性和慢性酒精暴露以及产前乙醇暴露对 谷胱甘肽的合成和释放并研究急性应激的影响 以及长期乙醇和产前乙醇暴露对谷胱甘肽的影响 与 NMDA 受体的相互作用。 最初，将进行研究 描述急性和慢性乙醇和胎儿乙醇的影响 暴露对大脑浓度和周转率降低（GSH）和 氧化型（GSSG）谷胱甘肽。 要研究的大脑区域是那些 高（小脑、大脑皮层、海马）、中级 NMDA 受体（纹状体）和低（脑桥髓质）密度。 研究是 还旨在确定乙醇对相互作用的影响 通过体外钙进入时添加谷胱甘肽（GSH 和 GSSG） NMDA 刺激分离神经元中的通道。 实验也将 进行以证明乙醇的机械效应，其中 受体结合研究将在新生儿和新生儿的膜上进行 成人大脑区域。 体外乙醇 (5 - 100 mM) 和 将研究慢性乙醇及其与谷胱甘肽的相互作用。 将进行实验研究乙醇和谷胱甘肽对 3H-CPP（NMDA 竞争位点）、3H-甘氨酸（共激动剂）的 Kd 和 Bmax 位点）和 H-MK-801（变构、通道抑制 PCP 位点）结合。 最后，研究旨在描述慢性病的影响 给怀孕的雌性大鼠注射乙醇 新生儿分离神经元中谷胱甘肽/NMDA 受体的相互作用 老鼠幼崽。 这些研究将解决可能的作用问题 含谷氨酸的肽可能在胎儿畸形中发挥作用 母亲乙醇暴露。