ETHANOL AND GLUTATHIONE ON NMDA RECEPTOR FUNCTION

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过程如神经元发育， 神经毒性和学习记忆。 在我们的研究和其他 实验室已经表明，NMDA受体介导的大脑过程 对乙醇的抑制非常敏感。 最近的工作在我 实验室已经表明，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， 钙通过NMDA刺激的离子通道进入。 发现Glucose 在大脑中的浓度很高，特别是在神经胶质细胞中。 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， 健壮的方式。 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 拟议研究的目的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酒精暴露对 谷胱甘肽的合成和释放，并研究急性 慢性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。 初期将进行研究， 描述急性和慢性乙醇以及胎儿乙醇的影响 暴露对脑内还原型谷胱甘肽（GSH）浓度和周转率的影响， 氧化型谷胱甘肽（GSSG）。 要研究的大脑区域将是那些 高（小脑，大脑皮层，海马），中 （纹状体）和低（脑桥-髓质）密度的NMDA受体。 研究是 还旨在确定乙醇对以下相互作用的影响： 谷胱甘肽（GSH和GSSG）在体外加入对钙进入通过 游离神经元中的NMDA刺激通道。 实验也将 进行，以证明乙醇的机械作用，其中 受体结合研究将在来自新生儿的膜上进行， 成人大脑区域 体外乙醇（5 - 100 mM）和 慢性乙醇及其与谷胱甘肽的相互作用将被研究。 实验将进行乙醇和谷胱甘肽的影响， 3 H-CPP（NMDA竞争位点）、3 H-甘氨酸（共激动剂）Kd和Bmax 位点）和H-MK-801（变构，通道抑制PCP位点）结合。 最后，研究的目的是描述慢性 对妊娠雌性大鼠进行乙醇给药 新生神经元谷胱甘肽/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， 含有谷氨酸的肽可能在胎儿畸形中起作用， 母亲酒精暴露。

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.