SELF REGULATORY ACTIONS OF ENDOGENOUS NITRIC OXIDE

这一建议调查的监管机制的反馈 调节一氧化氮（NO）的形成。具体来说，假设 将被测试的是：生理产生的NO调节其自身 通过调节涉及的细胞内途径的组分来合成 刺激神经元NO合酶。假设将被检验 使用m1毒蕈碱受体，因为这些受体与NO偶联 信号传导，并且该途径在学习和记忆中具有假定的作用。它 因此，研究NO合成的调节是重要的。三 具体目标如下：1）确定m1是否产生NO 受体激活导致受体偶联的抑制， 磷酸肌醇水解和钙信号传导。有证据表明 来自NO供体的NO减弱毒蕈碱受体介导的 磷酸肌醇水解2)确定NO的细胞机制- 诱导调节m1受体与这些第二信使的偶联 途径，和3）确定是否受体介导的NO的形成， 参与激动剂诱导的受体敏感性的长期变化。 实验将使用共表达神经元NO的细胞进行， 合成酶添加m1受体或表达m1受体，但不添加NO合成酶。 比较两个细胞群体产生的反应将提供 参与调节NO合成的细胞机制的信息 通过调节相关的信号通路。

This proposal investigates the regulatory mechanisms of feedback modulation of nitric oxide (NO) formation. Specifically, the hypothesis which will be tested is: physiologically produced NO regulates its own synthesis by modulating components of the intracellular pathways involved in stimulation of neuronal NO synthase. The hypothesis will be tested using m1 muscarinic receptors since these receptors couple to NO signaling and this pathway has a putative role in learning and memory. It is therefore important to study regulation of NO synthesis. Three specific aims will be pursued: 1) Determine if NO generated by m1 receptor activation results in dampening of receptor coupling to phosphoinositide hydrolysis and calcium signaling. There is evidence that NO from NO donors attenuates muscarinic receptor-mediated phosphoinositide hydrolysis. 2) Determine the cellular mechanisms of NO- induced regulation of coupling of m1 receptors to these second messenger pathways, and 3) Determine if receptor-mediated formation of NO is involved in agonist-induced long-term changes in receptor sensitivity. Experiments will be done using cells that either co-express neuronal NO synthase add ml receptors or express m1 receptors, but not NO synthase. Comparing responses produced by the two populations of cells will provide information on cellular mechanisms involved in regulating NO synthesis via modulation of related signaling pathways.