Biochemical anti-opioid action of NPFF2 receptors in rat spinal cord

• Published in: Neuroscience research 2007-05, Vol.58 (1), p.91-94
• Main Authors: Gouardères, Christine, Zajac, Jean-Marie
• Format: Article
• Language: English
• Subjects: Analgesics, Opioid - metabolism; Analgesics, Opioid - pharmacology; Animals; Binding, Competitive - drug effects; Binding, Competitive - physiology; Dose-Response Relationship, Drug; Enkephalin, Ala-MePhe-Gly- - pharmacology; Guanosine 5'-O-(3-Thiotriphosphate) - metabolism; Neurons - drug effects; Neurons - metabolism; Radioligand Assay; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled - drug effects; Receptors, G-Protein-Coupled - metabolism; Receptors, Neuropeptide - agonists; Receptors, Neuropeptide - drug effects; Receptors, Neuropeptide - metabolism; Spinal Cord - drug effects; Spinal Cord - metabolism
• ISSN: 0168-0102
• DOI: 10.1016/j.neures.2007.01.013

Neuropeptide FF (NPFF) agonists counteract the cellular opioid actions. We demonstrate for the first time a biochemical anti-opioid effect of NPFF receptors in the rat spinal cord by using the [(35)S]GTPgammaS binding assay in autoradiography. The mu agonist DAMGO as well as the potent and selective NPFF(2) agonist dNPA, stimulated [(35)S]GTPgammaS binding at different optimal GDP concentrations. dNPA decreased the effects induced by DAMGO alone; the maximal of G-protein coupling was decreased but not the potency of opioid agonist. We conclude that NPFF(2) receptors are coupled to G-protein in the rat spinal cord and could exert a molecular anti-opioid effect.