ENDOGENOUS LIGANDS FOR GLUTAMATE RECEPTORS IN BRAIN

谷氨酸（Glu）和天冬氨酸（Asp）被认为是重要的 兴奋性氨基酸（EAA）在脊椎动物神经系统。然而，在这方面， 它们作为充分表征的真正内源性配体的身份 EAA受体的亚型还没有确定。 研究 本提案中所描述的是旨在测试假设， 除了（或代替）Glu和Asp，具有C-末端Glu的小肽 和天冬氨酸，分别可能存在于大脑中，并可能作为 兴奋性神经递质或调节剂。这个假设是基于 初步研究表明，我们生产的两种抗Glu的抗血清， 和Asp分别识别。（1）Glu和Asp，（2）具有C- 末端Glu和Asp残基，（3）非内源性化合物， 区分EAA受体的亚类。 因此，quisqualate（Quis） 选择性阻断Glu抗血清、红藻氨酸（KA）的免疫染色 用Asp抗血清阻断，而N-甲基-D-Asp（NMDA）不能 被任一抗血清识别（一种新的抗NMDA的抗血清在 制备）。 我们研究的主要目的是利用这些抗血清 为了鉴定和表征特异性针对所述抗体的推定的内源性配体， 大鼠EAA受体的三种主要亚型（Quis、KA和NMDA） 个脑袋 首先，抗血清将进一步根据免疫反应性进行表征。 最佳抗原识别的分子要求，使用合成 二肽以及受体激动剂和拮抗剂。 二是 这些抗血清识别的内源性化合物将从 用来自抗血清的IgG级分制备的亲和柱上的脑。 最后是色谱。 酶免疫测定。光学和电子 显微免疫细胞化学和体外受体活化研究 将用于监测和补充这些程序。 这些研究的结果有望提供基本的新的 深入了解EAA神经传递的分子机制。 EAA受体新的内源性配体的鉴定将允许 更好地表征使用这些配体的神经元通路， 将有助于设计新的特异性EAA激动剂和拮抗剂 受体，并将提供线索，为理解和治疗这种 疾病过程为中风和低血糖后的脑损伤， 癫痫、亨廷顿舞蹈病和阿尔茨海默病。

L-Glutamate (Glu) and L-aspartate (Asp) are regarded as important excitatory amino acids (EAA) in the vertebrate nervous systems. However, their identity as the true endogenous ligands for the well characterized subtypes of EAA receptors is not established with certainty. The studies described in this proposal are designed to test the hypothesis that in addition to (or instead of) Glu and Asp, small peptides with C-terminal Glu and Asp, respectively, may be present in the brain and may act as excitatory neurotransmitters or modulators. This hypothesis is based on preliminary studies indicating that two antisera we have produced to Glu and Asp recognize,respectively. (1)Glu and Asp, (2) dipeptides with C- terminal Glu and Asp residues, (3) nonendogenous compounds which can discriminate between subclasses of EAA receptors. Thus, quisqualate (Quis) selectively blocks the immunostaining with the Glu antiserum, kainate (KA) blocks that with the Asp antiserum, while N-methyl-D-Asp (NMDA) is not recognized by either of the antisersa (a new antiserum to NMDA is in preparation). The principal goal of our studies is to use these antisera to identify and characterize putative endogenous ligands specific for the three major subtypes (Quis, KA, and NMDA) of EAA receptors in the rat brain. First, the antisera will be further characterized in terms of the molecular requirements for optimal antigen recognition, using synthetic dipeptides as well as receptor agonists and antagonists. Second, the endogenous compounds recognized by these antisera will be extracted from brain on affinity columns prepared with IgG fractions from the antisera. Finally, chromatography. Enzyme immunoassays. light and electron microscopic immunocytochemistry, and in vitro receptor activation studies will be used to monitor and complement these procedures. The results of these studies are expected to provide fundamental new insights into the molecular mechanisms of EAA neurotransmission. Identification of new endogenous ligands for EAA receptors will allow a better characterization of the neuronal pathways that use these ligands, will help in the design of new specific agonists and antagonists for EAA receptors and will provide clues for the understanding and therapy of such disease processes as brain damage following stroke and hypoglycemia, epilepsy, Huntington's chorea, and Alzheimer's disease.