Cardio-renal actions of novel nociceptin analogues

说明(申请人提供)：伤害素/孤儿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(利水)功能产生显著影响。利用N/OFQ多肽受体(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的途径在大脑和外周存在。根据本申请的建议，针对NOP受体(一种百日咳毒素敏感的G蛋白受体)选择性的新配体(肽和非肽)的开发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。需要检验的假设是，存在独立的中枢和外周NOP受体通路，影响心血管和肾脏功能，外周NOP受体通路被新的多肽和非肽配体选择性激活可以引起没有心血管/中枢神经系统不良影响的自由水利尿。这份修改后的申请中提出的调查将使用多学科方法来检验这一假设，这一方法可以通过N/OFQ研究领域的两名知名调查人员的合作努力成功实现，他们是P.I.和多梅尼科·雷戈利博士。这将需要利用多肽和非肽化学来合成新型的NOP受体配体，这将用于阐明N/OFQ和NOP受体配体在脑、外周和肾脏中的生物学作用、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，并在体内分析这些新的NOP受体配体产生的心血管和肾脏反应。转基因NOP受体基因敲除小鼠(整个动物/组织)的使用将为了解N/OFQ和NOP配体在每个部位的作用提供一种创新的方法。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价将探索NOP受体系统的药理学以及NOP受体配体引起不同心血管和肾脏反应的潜在信号通路。最后，将探索新型外周作用的NOP配体在加压素过量状态下产生治疗性水利尿的可能性。预计这一领域的工作将为治疗与液体滞留和/或低钠/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.