Table of Contents
Journal of Amino Acids
Volume 2011 (2011), Article ID 836569, 10 pages
Review Article

NOP Receptor Ligands as Potential Agents for Inflammatory and Autoimmune Diseases

1Laboratório de Farmacologia Comportamental, Programa de Pós-graduação em Desenvolvimento e Inovação Tecnológica em Medicamentos, Departamento de Biofísica e Farmacologia, Centro de Biociências, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, RN, Brazil
2Laboratório de Biologia Celular e Imunologia, Programa de Pós-Graduação em Ciências da Saúde, Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, 90050-170 Porto Alegre, RS, Brazil

Received 8 February 2011; Revised 31 August 2011; Accepted 24 September 2011

Academic Editor: Andreas Wyttenbach

Copyright © 2011 Elaine C. Gavioli and Pedro R. T. Romão. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Nociceptin/orphanin FQ (N/OFQ) is a seventeen-amino acid peptide that is the endogenous ligand of a G-protein-coupled receptor (NOP). Various immune cells express the precursor protein and secrete N/OFQ as well as display binding sites for this peptide. The functional capacity of NOP receptor was demonstrated in vitro and in vivo studies by the ability of N/OFQ to induce chemotaxis of immune cells, to regulate the expression of cytokines and other inflammatory mediators, and to control cellular and humoral immunity. In this context, N/OFQ could modulate the outcome of some inflammatory diseases, such as sepsis and autoimmune pathologies by mechanisms not clearly elucidated yet. In fact, human body fluid revealed increased levels of N/OFQ under sepsis, arthritis, and Parkinson's diagnose. Preclinical studies pointed to the blockade of NOP receptor signaling as successful in treating these experimental conditions. Further preclinical and clinical studies are required to investigate the potential of NOP ligands in treating inflammatory diseases.