AIM: To characterize the antinociceptive action of the novel melatonin receptor (MT) agonists, Neu-P11 and Neu-P12 in animal models of visceral pain. METHODS: Visceral pain was induced by intracolonic (ic) application...AIM: To characterize the antinociceptive action of the novel melatonin receptor (MT) agonists, Neu-P11 and Neu-P12 in animal models of visceral pain. METHODS: Visceral pain was induced by intracolonic (ic) application of mustard oil or capsaicin solution or by intraperitoneal (ip) administration of acetic acid. Neu-P11, Neu-P12, or melatonin were given ip or orally and their effects on pain-induced behavioral responses were evaluated. To identify the receptors involved, the non-selective MT1/MT2 receptor antagonist luzindole, the MT2 receptor antagonist 4-P-PDOT, or the mu-opioid receptor antagonist naloxone were injected ip or intra-cerebroventricularly (icv) prior to the induction of pain. RESULTS: Orally and ip administered melatonin, Neu-P11, and Neu-P12 reduced pain responses in a dose-dependent manner. Neu-P12 was more effective and displayed longer duration of action compared to melatonin. The antinociceptive effects of Neu-P11 or Neu-P12 were antagonized by ip or icv. administered naloxone. Intracerebroventricularly, but not ip administration of luzindole or 4-P-PDOT blocked the antinociceptive actions of Neu-P11 or Neu-P12. CONCLUSION: Neu-P12 produced the most potent and long-lasting antinociceptive effect. Further development of Neu-P12 for future treatment of abdominal pain seems promising. (C) 2014 Baishideng Publishing Group Co., Limited. All rights reserved.展开更多
基金Supported by The University of Calgary Research Grant Committee(to Storr M)the Deutsche Forschungsgemeinschaft(STO 645/6-1 and 645/9-1 to Storr M)the Iuventus Plus program of the Polish Ministry of Science and Higher Education(0119/IP1/2011/71 and 0107/IP1/2013/72 to Fichna J)
文摘AIM: To characterize the antinociceptive action of the novel melatonin receptor (MT) agonists, Neu-P11 and Neu-P12 in animal models of visceral pain. METHODS: Visceral pain was induced by intracolonic (ic) application of mustard oil or capsaicin solution or by intraperitoneal (ip) administration of acetic acid. Neu-P11, Neu-P12, or melatonin were given ip or orally and their effects on pain-induced behavioral responses were evaluated. To identify the receptors involved, the non-selective MT1/MT2 receptor antagonist luzindole, the MT2 receptor antagonist 4-P-PDOT, or the mu-opioid receptor antagonist naloxone were injected ip or intra-cerebroventricularly (icv) prior to the induction of pain. RESULTS: Orally and ip administered melatonin, Neu-P11, and Neu-P12 reduced pain responses in a dose-dependent manner. Neu-P12 was more effective and displayed longer duration of action compared to melatonin. The antinociceptive effects of Neu-P11 or Neu-P12 were antagonized by ip or icv. administered naloxone. Intracerebroventricularly, but not ip administration of luzindole or 4-P-PDOT blocked the antinociceptive actions of Neu-P11 or Neu-P12. CONCLUSION: Neu-P12 produced the most potent and long-lasting antinociceptive effect. Further development of Neu-P12 for future treatment of abdominal pain seems promising. (C) 2014 Baishideng Publishing Group Co., Limited. All rights reserved.
