NEUROPEPTIDE Y MODULATION OF ADRENOMEDULLARY SECRETION

我们建议进行的研究的整体意义，是进一步 对多肽作用的生理相关性的理解 神经递质功能及对肾上腺髓质分泌的影响 很特别。初步研究表明，低浓度(1×10-8M) 神经肽Y(NPY)抑制尼古丁刺激的肾上腺髓质 分泌物。我们的假设是NPY在肾上腺髓质发挥作用 调节烟碱受体刺激的儿茶酚胺分泌。这个 具体目标是：1)划定效果和结构要求 NPY对烟碱受体兴奋的影响，2)确定NPY在 嗜铬细胞影响分泌，3)描述NPY结合及其 对激动剂与尼古丁受体结合的影响，以及4)识别和 表征G结合蛋白与肌醇磷脂周转的作用 在神经肽Y的调节作用中。NPY的调节作用将是 通过测量尼古丁受体诱导的分泌来检查 肾上腺素、去甲肾上腺素和脑啡肽样肽(ME-IRM) 培养的牛嗜铬细胞。儿茶酚胺和ME-IRM的分泌将 高效液相色谱-电化学法测定 检测，并使用放射免疫化学技术使用特定的 抗(Met5)-脑啡肽抗体。神经肽Y对分泌的影响 将通过研究它在各种情况下的行动来确定 尼古丁激动剂，它对刺激分泌的药物通过 除了尼古丁受体和截短形式的NPY和 与NPY具有序列同源性的多肽。内源性的作用 将通过使用抗体和反义RNA来检测NPY NPY。NPY对分泌的调节作用机制可能是 通过研究NPY对烟碱受体结合和On的影响 第二信使产生的变化(G结合蛋白， 磷脂酰肌醇转运量)，可能参与转导 在烟碱受体刺激期间收到的信息。我们将采用 细胞培养、放射免疫分析、高效液体技术 层析，反义寡核苷酸探针，放射受体结合， 离子交换层析和薄层层析。健康 拟议研究的相关后果是深远的，因为 神经肽在生理和病理中的不同作用，例如， 神经调节缺陷导致高血压或精神障碍。

The overall significance of our proposed studies is to further the understanding of the physiological relevance of peptide action in neurotransmitter function in general and on adrenomedullary secretion in particular. Pilot studies have shown that low concentrations (1 X 10-8 M) of neuropeptide Y (NPY) inhibit nicotine stimulated adrenomedullary secretion. Our hypothesis is that NPY exerts its effect on adrenomedullary catecholamine secretion by modulating nicotinic receptor stimulation. The specific aims are to : 1) delineate the effects and structural requirements of NPY on nicotinic receptor stimulation, 2) determine whether NPY in chromaffin cells influences secretion, 3) describe NPY binding and its effect on agonist binding to the nicotinic receptor, and 4) identify and characterize the role of G-binding proteins and phosphoinositide turnover in the modulatory action of NPY. The modulatory effect of NPY will be examined by measuring the nicotine receptor-induced secretion of epinephrine, norepinephrine and the enkephalin-like peptides (ME-IRM) using cultured bovine chromaffin cells. Catecholamine and ME-IRM secretion will be measured by high performance liquid chromatography with electrochemical detection, and with radioimmunochemical techniques using a specific antibody to (Met5)-enkephalin, respectively. NPY influence on secretion will be determined by studying it's action in the presence of various nicotinic agonists, it's action on agents stimulating secretion through other than nicotinic receptors and the effect of truncated forms of NPY and peptides possessing sequence homologies with NPY. The role of endogenous NPY will be examined through the use of antibodies and antisense RNA to NPY. The mechanism of the modulatory effect of NPY on secretion will be examined by studying the effect of NPY on nicotinic receptor binding and on changes produced in the second messengers (G-binding proteins, phosphoinositide turnover) that may be involved in the transduction of the message received during nicotinic receptor stimulation. We will employ the techniques of cell culture, radioimmunoassay, high performance liquid chromatography, antisense oligonucleotide probes, radioreceptor binding, ion-exchange chromatography and thin layer chromatography. The health related consequences of the proposed studies are far-reaching due to the varied roles suggested for neuropeptides in physiology and pathology, e.g., defective neuronal regulation leading to hypertension or mental disorders.