PSYCHOTROPIC DRUGS AND RECEPTOR SENSITIVITY CHANGES

拟议的研究的主要长期目标是了解 M碱乙酰胆碱的神经传递的分子基础， 组胺H1和缓激肽受体，其激动剂可能是 中枢神经系统中的神经递质。此外，最近在 申请人的实验室已经发现了凝血酶，中央 止血中的酶及其受体的研究。所有这些都是 受体被各自的配体激活时刺激环状GMP 被广泛研究的小鼠神经母细胞瘤克隆(N1E-115)的合成。这个 受体激活和环状GMP的产生之间的联系正在被 在这些研究中寻找，因为我们最近的数据表明这种联系不是 CA++AS是普遍认为的。部分基于凝血酶的结果， 我们计划用克隆的N1E-115细胞来检验以下假设。 介导环状GMP合成的受体最终通过刺激 磷脂酶A2活性，释放花生四烯酸(AA)，然后 代谢成一种刺激量子酸环化酶的产物。 此外，我们假设另一种AA代谢物是稍后 人工合成，抑制环化酶，从而关闭 受体介导的反应(脱敏)。还建议进行研究，以 凝血酶和缓激肽与其相互作用的进一步表征 这些细胞上的受体。 使用的方法包括细胞培养；测量用前体标记 完整细胞的环状GMP合成；层析技术包括 薄层高效液、气相色谱检测 正常大鼠细胞膜磷脂组成和AA代谢的变化 暴露于各种激动剂的细胞；气相色谱/质谱仪 鉴定可能影响氨基酸活性的AA代谢物 鸟苷环化酶；和放射性配基结合分析来表征 凝血酶和缓激肽与其受体的相互作用。 在所有这些研究中，将测试各种精神治疗药物 它们对受体部位以外发生的事件的影响。这些研究 将增加我们对某些受体的了解，这些受体受 许多抗抑郁药和神经镇静剂(毒鼠碱和组胺H1)和一种 (毒碱)这似乎与记忆和学习有关。在……里面 此外，这项工作的结果可能会导致我们对基础的理解 某些神经递质敏感度的短期变化 感受器。

The proposed research has as its major long-term goal the understanding of the molecular basis of neurotransmission at muscarinic acetylcholine, histamine H1 and bradykinin receptors, the agonists for which are putative neurotransmitter in the CNS. In addition, a recent discovery in the applicant's laboratory has led to the inclusion of thrombin, the central enzyme in hemostasis, and its receptor in these studies. All these receptors when activated by their respective ligands stimulate cyclic GMP synthesis by a widely-studied murine neuroblastoma clone (N1E-115). The link between receptor activation and the production of cyclic GMP is being sought in these studies since our recent data show that this link is not Ca++ as is generally thought. Based in part on the results with thrombin, we plan to test the following hypothesis with clone N1E-115 cells. Receptors that mediate cyclic GMP synthesis do so by ultimately stimulating phospholipase A2 activity, liberating arachidonic acid (AA) which is then metabolized into a product that stimulates quanylate cyclase. Additionally, we hypothesize that another AA metabolite is later synthesized which inhibits the cyclase, thereby turning off the receptor-mediated response (desensitization). Studies are also proposed to characterize further the interactions of thrombin and bradykinin with their receptors on these cells. Methods to be used include cell culture; precursor labeling for measuring cyclic GMP synthesis by intact cells; chromatographic techniques including thin-layer, highperformance liquid and gas chromatography to measure changes in the membrane phospholipid profile and AA metabolism of intact cells exposed to various agonists; gas chromatography/mass spectrometry to identify putative metabolites of AA which may affect the activity of guanylate cyclase; and radioligand binding assays to characterize the interactions of thrombin and bradykinin with their receptors. In all these studies, various psychotherapeutic drugs will be tested for their effects on events that occur beyond the receptor site. These studies will increase our understanding of certain receptors that are affected by many antidepressants and neuroleptics (muscarinic and histamine H1) and one (muscarinic) that seems to be involved with memory and learning. In addition, results from this work may lead to our understanding of the basis of short-term changes in the sensitivity of certain neurotransmitter receptors.