PSYCHOTROPIC DRUGS & MUSCARINIC RECEPTOR TYPES

在我们最初的研究中，我们发现人神经母细胞瘤（SH-SY 5 Y） 细胞系一致地表达高密度的mAChR（约220 fmol/mg蛋白质或25，000个受体/细胞）。大多数的mAChR在 SH-SY 5 Y细胞对[3 H]PZ表现出高亲和力，表明[3 H] PZ具有M1特性。 这些毒蕈碱受体。据我们所知，SH-SY 5 Y细胞系是 仅具有高亲和力[3 H]PZ结合至细胞上的mAChR的细胞系 完整的细胞SH-SY 5 Y细胞具有功能性PI系统， 腺苷酸环化酶系统。这些效应器系统的存在提供了一个 研究M1效应器耦合机制的独特机会 受体在同质神经元细胞系。我们的初步数据显示 这些M1受体与PI系统相连在本提案中，我们 将进一步研究mAChRs在以下方面的药理学特性： SY-SY 5 Y细胞使用几种新的选择性毒蕈碱配体和比较 这些数据与转染的B82系统，被认为只含有 一种mAChr。也就是说，M1.此外，我们还将研究第二个 信使系统耦合到受体，以获得更好的 了解mAChRs在两种疾病中功能的分子基础， 细胞系虽然我们最初的药理学研究表明， SH-SY 5 Y细胞上的主要mAChR是M1型，因为 可能不止一个mAChR对PZ显示出高亲和力（40）， 这种受体的明确定义需要了解其主要的 通过基因克隆和测序来构建。然而，这只会在 如果SH-SY 5 Y细胞系中的mAChR是唯一的。 本研究将产生表达恒定M1群体的克隆 具有天然M1药理学和生物学特性的受体 受体。这项研究将提供有关功能的深入信息， 神经mAChRs的机制及其遗传调控。这些知识 将在CNS疾病的药物治疗中具有重要性， 胆碱能缺陷如阿尔茨海默型老年痴呆 （SDAT）、亨廷顿氏病（HD）和帕金森氏病（PD）。此外，委员会认为， 这些细胞系将用作开发选择性 作用于单一类型的mAChR从而改善治疗效果的药物 同时减少副作用。

In our initial studies, we found that the human neuroblastoma (SH-SY5Y) cell line consistently expresses a high density of mAChRs (about 220 fmol/mg protein or 25,000 receptors/cell). Most of the mAChRs in the SH-SY5Y cells showed high affinity for [3H]PZ, suggesting an M1 nature of these muscarinic receptors. To our knowledge, the SH-SY5Y cell line is the only cell line with high affinity [3H]PZ binding to_the mAChRs on the intact cells. The SH-SY5Y cells have a functional PI system and an adenylate cyclase system. The existence of these effector systems offers a unique opportunity to study the effector coupling mechanisms of the M1 receptors in a homogeneous neuronal cell line. Our initial data suggest that these M1 receptors are coupled to the PI system. In this proposal, we will further examine the pharmacological properties of the mAChRs in SY-SY5Y cells using several new selective muscarinic ligands and compare these data with a transfected B82 system which is thought to contain only one type of mAChr. i.e., M1. Furthermore, we will also examine the second messenger system coupled to the receptors in order to obtain a better understanding of the molecular basis for the function of the mAChRs in both cell lines. Although our initial pharmacological studies indicate that the predominant mAChRs on the SH-SY5Y cells are of the M1 type, since there could be more than one mAChR showing high affinity for PZ (40), an unambiguous definition of this receptor requires a knowledge of its primary structure by gene cloning and sequencing. However, this will only be done if the mAChRs in the SH-SY5Y cell line is unique. This study will yield clone(s) which express a constant population of M1 receptors with pharmacological and biological properties of the native M1 receptors. This study will provide in depth information on the functional mechanism of neural mAChRs and their genetic regulation. This knowledge will have importance in the drug treatment of CNS disorders with cholinergic deficits such as senile dementia of the Alzheimer's type (SDAT), Huntington's disease (HD) and Parkinson's disease(PD). Furthermore, these cell lines will be used as models for the development of selective drugs which act at a single type of mAChR thereby improving therapeutic effects while reducing side effects.