PSYCHOTROPIC DRUGS AND RECEPTOR SENSITIVITY CHANGES

拟议的研究的主要长期目标是了解 毒蕈碱乙酰胆碱神经传递的分子基础， 组胺H1和缓激肽受体，其激动剂是推定的 中枢神经系统中的神经递质。 此外，最近的一项发现 申请人的实验室已经导致包括凝血酶， 止血酶及其受体。 所有这些 受体在被其各自的配体激活时刺激环GMP 由广泛研究的鼠神经母细胞瘤克隆（N1 E-115）合成。 的 受体激活和环GMP产生之间的联系正在被 因为我们最近的数据显示，这种联系并不是 Ca++一般认为。 部分基于凝血酶的结果， 我们计划用克隆N1 E-115细胞检验以下假设。 介导环GMP合成的受体通过最终刺激 磷脂酶A2活性，释放花生四烯酸（AA），然后 代谢成刺激quanylate环化酶的产物。 此外，我们假设另一种AA代谢物是在 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， 进一步表征凝血酶和缓激肽与它们的 这些细胞上的受体。 使用的方法包括细胞培养;前体标记用于测量 完整细胞的环GMP合成;色谱技术，包括 薄层、高效液相和气相色谱法测定 膜磷脂分布和AA代谢的变化 暴露于各种激动剂的细胞;气相色谱/质谱法， 确定可能影响活性的AA的推定代谢物 鸟苷酸环化酶;和放射性配体结合测定，以表征 凝血酶和缓激肽与其受体的相互作用。 在所有这些研究中，各种精神治疗药物将被测试， 它们对发生在受体位点之外的事件的影响。 这些研究 将增加我们对某些受体的了解， 许多抗抑郁药和神经安定药（毒蕈碱和组胺H1）和一种 （毒蕈碱）似乎与记忆和学习有关。 在 此外，这项工作的结果可能会导致我们理解的基础 某些神经递质敏感性的短期变化 受体。

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.