PSYCHOTROPIC DRUGS & MUSCARINIC RECEPTOR TYPES

在我们的初步研究中，我们发现人类神经母细胞瘤(SH-SY5Y) 细胞系持续表达高密度的mAChRs(约220 Fmol/mg蛋白或25,000个受体/细胞)。大多数的mAChR在 SH-SY5Y细胞对[~3H]PZ表现出高亲和力，提示其具有M1性质。 这些毒扁豆碱受体。据我们所知，SH-SY5Y细胞系是 唯一与mAChRs高亲和力结合的细胞系 完好无损的细胞。SH-SY5Y细胞有一个有效的PI系统和一个 腺苷环化酶系统。这些效应器系统的存在提供了一种 研究M1效应器耦合机制的难得机会 同种神经细胞系中的受体。我们的初步数据显示 这些M1受体连接到PI系统。在这项提案中，我们 将进一步研究mAChRs的药理特性 几种新的选择性M胆碱配体在SY-SY5Y细胞中的应用及比较 这些数据与被认为只包含 一种类型的mAChr。即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 对两者mAChRs功能的分子基础的理解 细胞系。虽然我们最初的药理研究表明， SH-SY5Y细胞上的主要mAChRs是M1型，因为有 可以是一个以上对PZ(40)具有高亲和力的mAChR，以及 这种受体的明确定义需要了解它的主要成分 通过基因克隆和测序来构建。然而，这将只会被执行 如果SH-SY5Y细胞系中的mAChRs是唯一的。 这项研究将产生表达恒定种群M1的克隆(S 天然M1受体的药理和生物学特性 感受器。这项研究将提供有关功能的深入信息 神经型mAChRs的机制及其遗传调控。这一知识 将在中枢神经系统疾病的药物治疗中具有重要意义 胆碱能缺陷，如阿尔茨海默型老年性痴呆 (SDAT)、亨廷顿病(HD)和帕金森病(PD)。此外， 这些细胞系将被用作发展选择性 作用于单一类型的mAChR从而提高治疗效果的药物 在减少副作用的同时产生效果。

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.