title: Sulpiride attenuates ranatensin-M-induced antinociception.
abstract: Intracerebroventricular (icv) administration of ranatensin-M (RM), a bombesin-like peptide isolated from the skin of Chinese frog Rana margaratae, produced a dose-dependent prolongation in the hot-plate latency in mice. Naloxone 1, 2, or 10 mg.kg-1 ip failed to antagonize the effects of RM. However, RM-induced antinociception was attenuated by pretreatment with sulpiride (Sul, 100 mg.kg-1, ip), a selective DA2 receptor blocker. Sul (100 mg.kg-1, ip) did not affect hot-plate latencies when administered alone. Sch 23390 (0.2 mg.kg-1, ip), a selective DA1 receptor blocker, did not significantly affect RM-induced antinociception. The results suggest that RM-induced antinociception may be mediated by dopamine neurotransmission within the CNS and that it is mainly the D2 receptor which was involved in this effects.
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences.
authors.forename: X Z
authors.initials: XZ
authors.lastname: Zhu
authors.forename: X Q
authors.initials: XQ
authors.lastname: Ji
authors.forename: S X
authors.initials: SX
authors.lastname: Wu
authors.forename: G
authors.initials: G
authors.lastname: Zou
mesh_terms: D000595:Amino Acid Sequence; D000698:Analgesia; D000700:Analgesics / Q000037:antagonists & inhibitors*; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005260:Female; D007276:Injections, Intraventricular; D051379:Mice; D008969:Molecular Sequence Data; D009270:Naloxone / Q000494:pharmacology; D009842:Oligopeptides / Q000037:antagonists & inhibitors*; D010146:Pain / Q000503:physiopathology*; D012684:Sensory Thresholds / Q000187:drug effects; D013469:Sulpiride / Q000494:pharmacology*
chemical_list: D000700:Analgesics; D001552:Benzazepines; D009842:Oligopeptides; C073980:ranatensin M; D009270:Naloxone; D013469:Sulpiride