Cardio-renal actions of novel nociceptin analogues

描述（由申请人提供）：Nociceptin/orphanin FQ （N/OFQ）是一种内源性阿片样肽，对动物的心血管（低血压、心动过缓、交感神经抑制）和肾脏排泄（水利尿）功能有显著作用。利用N/OFQ肽受体（NOP）的选择性配体，我们已经获得证据表明，N/OFQ影响心血管和肾脏功能在大脑和外周存在不同的途径。正如本应用中所提出的，开发新的配体（肽和非肽）选择性NOP受体，百日咳毒素敏感的g蛋白受体，将为系统研究这些组织/系统特异性途径提供必要的基本药理学工具。需要验证的假设是，存在影响心血管和肾脏功能的独立中枢和外周NOP受体通路，并且用新型肽和非肽配体选择性激活外周NOP受体通路可以引起无不良心血管/中枢神经系统影响的自由水利尿。本修订申请中提出的调查将使用多学科方法来验证这一假设，这可以通过N/OFQ研究领域的两位知名研究者的合作努力成功实现，他们是p.i.和Domenico Regoli博士。这将需要利用肽和非肽化学合成新的NOP受体配体，这将用于阐明N/OFQ和NOP受体配体在大脑、外周和肾脏中的生物作用、组织分布和信号转导途径。这些研究将采用分子、细胞和经典药理学方法，涉及分离的器官、组织和整个动物；以及这些新型NOP受体配体产生的心血管和肾脏反应的体内分析。使用转基因NOP受体敲除小鼠（整个动物/组织）将提供一种创新的方法来了解N/OFQ和NOP配体在每个位点的作用。在不同的体外生物测定和细胞培养中对N/OFQ和NOP受体配体的药理学评估将探索NOP受体系统的药理学以及NOP受体配体引发各种心血管和肾脏反应的潜在信号通路。最后，新型外周作用NOP配体在加压素过量状态下产生治疗性水利尿的潜力将被探索。预计这一领域的工作将为治疗与液体潴留和/或低钠血症/低钾血症相关的不同病理状态提供新的策略。

DESCRIPTION (provided by applicant): Nociceptin/orphanin FQ (N/OFQ) is an endogenous opioid-like peptide that produces marked effects on cardiovascular (hypotension, bradycardia, sympathoinhibition) and renal excretory (water diuresis) function in animals. Using selective ligands for the N/OFQ peptide receptor (NOP), we have obtained evidence that there exist separate pathways in the brain and periphery by which N/OFQ affects cardiovascular and renal function. As proposed in this application, the development of new ligands (peptide and non-peptide) selective for the NOP receptor, a pertussis toxin-sensitive G-protein receptor, will provide the basic pharmacological tools necessary to systematically study these tissue/system specific pathways. The hypothesis to be tested is that there exist separate central and peripheral NOP receptor pathways that affect cardiovascular and renal function, and that selective activation of the peripheral NOP receptor pathway with novel peptide and non-peptide ligands can evoke a free-water diuresis devoid of adverse cardiovascular/CNS effects. The investigations proposed in this amended application will test this hypothesis using a multidisciplinary approach that can be successfully achieved by the collaborative efforts of two established investigators in the N/OFQ research field, these being the P.I., and Dr. Domenico Regoli. This will entail the synthesis of novel NOP receptor ligands using peptide and non-peptide chemistry, which will be used to elucidate the biological actions, tissue distribution and signal transduction pathways of N/OFQ and NOP receptor ligands in the brain, periphery and kidneys. These studies will employ molecular, cellular and classical pharmacological approaches involving isolated organs, tissues and whole animals; and in vivo analysis of the cardiovascular and renal responses produced by these novel NOP receptor ligands. The use of genetically modified transgenic NOP receptor knockout mice (whole animal/tissue) will provide an innovative approach to understand the effects of N/OFQ and NOP ligands at each site. The pharmacological evaluation of N/OFQ and NOP receptor ligands in different in vitro bioassays and cell culture will explore the pharmacology of the NOP receptor system and the underlying signaling pathways by which NOP receptor ligands elicit diverse cardiovascular and renal responses. Finally, the potential for novel peripherally acting NOP ligands to produce a therapeutic water diuresis in states of vasopressin excess will be explored. It is anticipated that work in this area will provide new strategies for the treatment of different pathological states associated with fluid retention and/or hyponatremia/hypokalemia.