Biochemical anti-opioid action of NPFF2 receptors in rat spinal cord.
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.
Gouardères
Christine
C
Institut de Pharmacologie et de Biologie Structurale, CNRS UMR 5089, 205 Route de Narbonne, 31077 Toulouse Cedex, France.
Zajac
Jean-Marie
JM
D000701:Analgesics, Opioid / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000187:drug effects / Q000378:metabolism; D018013:Receptors, Neuropeptide / Q000819:agonists / Q000187:drug effects / Q000378:metabolism*; D013116:Spinal Cord / Q000187:drug effects / Q000378:metabolism*
D000701:Analgesics, Opioid; D043562:Receptors, G-Protein-Coupled; D018013:Receptors, Neuropeptide; C083929:neuropeptide FF receptor; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D016244:Guanosine 5'-O-(3-Thiotriphosphate)