Protective and worsening peripheral nociceptin/orphanin FQ receptor-mediated effect in a rat model of experimental colitis.

Abstract

Nociceptin/orphanin FQ (N/OFQ) and nociceptin orphanin peptide (NOP) receptors represent an endogenous system modulating gastrointestinal functions and inflammation. We investigated the peripheral effect of N/OFQ and of UFP-101, the NOP antagonist, in a model of colitis induced by TNBS (2,4,6 trinitrobenzenesulphonic acid; 60mg/kg). Male rats received two intraperitoneal injections per day of N/OFQ, UFP-101 or saline for 3 days after colitis induction. Four days after TNBS, animals were sacrificed and colonic histological damage, myeloperoxidase (MPO) activity and cytokine (IL-1β and IL-10) levels were evaluated. N/OFQ plasmatic levels were assessed by radioimmunoassay. TNBS increased all the inflammatory variables considered. In colitic rats, N/OFQ (0.02 and 0.2nmol/kg) improved microscopic damage, MPO activity and decreased IL-1β levels in comparison with TNBS group, whereas at the highest dose (20nmol/kg) the peptide worsened colitis. UFP-101 at the dose of 1nmol/kg, without pharmacological activity, antagonised the protective effect of N/OFQ (0.2nmol/kg) on colitis, but at a dose level of 3 and 10nmol/kg worsened inflammation, revealing the endogenous N/OFQergic system protective role. N/OFQ plasmatic levels were not modified in TNBS-treated rats compared with controls, whereas they were reduced in rats treated with the doses of UFP-101 aggravating colitis. In conclusion, peripheral low doses of N/OFQ have a beneficial effect on colonic inflammation in rats. In contrast, N/OFQ at a dose 100-1000-fold higher than those that protect worsens colitis, probably through different mechanisms. The peripheral N/OFQergic system can represent a new field of investigation in some intestinal inflammatory conditions.

• Authors: Carla Petrella, Chiara Giuli, Maria Broccardo, Helene Eutamene, Christel Cartier, Mathilde Leveque, Andrea Bedini, Santi Spampinato, Lionel Bueno, Vassilia Theodorou, Giovanna Improta, Simona Agostini
• Journal: Pharmacological research (Pharmacol Res) Vol. 70 Issue 1 Pg. 72-9 (Apr 2013) ISSN: 1096-1186 [Electronic] Netherlands
• PMID: 23353033 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2013 Elsevier Ltd. All rights reserved.

Chemical References

• (Nphe(1),Arg(14),Lys(15))N-OFQ NH(2)
• Cytokines
• Opioid Peptides
• Receptors, Opioid
• Trinitrobenzenesulfonic Acid
• Nociceptin Receptor
• Oprl protein, rat

Topics

• Animals
• Colitis (chemically induced, metabolism, pathology, prevention & control)
• Cytokines (immunology)
• Disease Models, Animal
• Dose-Response Relationship, Drug
• Intestinal Mucosa (drug effects, immunology, metabolism)
• Male
• Opioid Peptides (administration & dosage, antagonists & inhibitors, blood, pharmacology)
• Protein Binding
• Radioimmunoassay
• Rats
• Rats, Wistar
• Receptors, Opioid (metabolism)
• Trinitrobenzenesulfonic Acid (pharmacology)
• Nociceptin Receptor
• Nociceptin