title: Supraspinal administration of apelin-13 induces antinociception via the opioid receptor in mice.
abstract: The effect of apelin-13 on pain modulation at the supraspinal level was investigated in mice using the tail immersion test. Intracerebroventricular (i.c.v.) administration of apelin-13 (0.3, 0.5, 0.8 and 3 microg/mouse) produced a dose- and time-related antinociceptive effect. This effect was significantly antagonized by the APJ receptor antagonist apelin-13(F13A), indicating an APJ receptor-mediated mechanism. Furthermore, naloxone, beta-funaltrexamine and naloxonazine, could reverse the analgesic effect. However, naltrindole or nor-binaltorphimine could not reverse the effect, suggesting that mu opioid receptor (primarily mu(1) opioid receptor subtype) is involved in the analgesic response evoked by apelin-13. Moreover, i.c.v. administration of apelin-13 potentiated the analgesic effect induced by morphine (i.c.v., 5 microg/kg) and this potentiated effect can be also reversed by naloxone.
authors.affiliation: Department of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.forename: Haiting
authors.initials: H
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Fan
authors.forename: Qiang
authors.initials: Q
authors.lastname: Chen
mesh_terms: D000698:Analgesia; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D000075244:Apelin Receptors; D007276:Injections, Intraventricular; D036341:Intercellular Signaling Peptides and Proteins / Q000008:administration & dosage* / Q000494:pharmacology* / Q000627:therapeutic use*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009020:Morphine / Q000494:pharmacology; D009292:Narcotic Antagonists; D010146:Pain / Q000188:drug therapy*; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors; D011957:Receptors, Opioid / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D000075244:Apelin Receptors; C491285:Aplnr protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D009292:Narcotic Antagonists; D043562:Receptors, G-Protein-Coupled; D011957:Receptors, Opioid; C495199:apelin-13 peptide; D009020:Morphine