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元过程，如神经元发育， 神经毒性和学习记忆。在我们和其他国家的研究 实验室已经表明，NMDA受体在大脑中介导的过程 对乙醇的抑制高度敏感。我最近的工作 实验室已表明谷胱甘肽(谷氨酰半胱氨酸甘氨酸) 以一种明显的竞争性方式刺激NMDA受体以增强 钙离子通过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 强健的态度。结合我实验室的最新结果， 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。整体而言 拟议研究的目标将是描述相互作用的特征 谷胱甘肽对NMDA受体功能的影响 急、慢性酒精暴露和产前酒精暴露对儿童的影响 谷胱甘肽的合成和释放及其对急性毒性的影响 慢性酒精和产前酒精暴露对谷胱甘肽的影响 与NMDA受体的相互作用。初步来说，我们会进行研究，以 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)浓度和周转的影响 氧化(GSSG)谷胱甘肽。要研究的大脑区域将是那些 高(小脑、大脑皮层、海马体)、中 (纹状体)和低密度(脑桥-髓质)的NMDA受体。研究是 也被设计用来确定乙醇对 体外加入谷胱甘肽(GSH和GSSG)对钙内流的影响 NMDA刺激的神经细胞通道。实验也将是 以演示乙醇的机械效应，其中 将在新生儿和婴儿的胎膜上进行受体结合研究 成人的大脑区域。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。 将对乙醇和谷胱甘肽的影响进行实验 ~3H-CPP(NMDA竞争位点)、~3H-甘氨酸(共激动剂)的Kd和Bmax 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疾病的影响。 给怀孕的雌性大鼠注射乙醇 新生分离神经元中谷胱甘肽/NMDA受体的相互作用 幼鼠。这些研究将解决可能扮演的角色的问题 含有谷氨酸的多肽可能在胎儿畸形中起作用 母亲接触酒精。

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.