Involvement of endogenous opioid systems in nociceptin-induced spinal antinociception in rats |
| |
Authors: | Yu Long-Chuan Lu Jiang-Teng Huang Yan-Hua Meuser Thomas Pietruck Christian Gabriel Anja Grond Stefan Pierce Palmer Pamela |
| |
Institution: | Department of Anesthesia and Perioperative Care, University of California, Box 0464, Room S-455 513 Parnassus Avenue, San Francisco, CA 94143, USA. |
| |
Abstract: | The present study investigates the involvement of opioid receptors in the antinociceptive effects of nociceptin in the spinal cord of the rat. Intrathecal administrations of 5 and 10 nmol of nociceptin significantly increase the withdraw response latencies to noxious thermal and mechanical stimulations. This nociceptin-induced antinociceptive effect is significantly attenuated by intrathecal injection of (Nphe(1))nociceptin(1-13)-NH(2), a selective antagonist of the nociceptin receptor (opioid receptor-like receptor ORL1), indicating an ORL1 receptor-mediated mechanism. This antinociceptive effect is also significantly attenuated by intrathecal injections of naloxone (a nonselective opioid receptor antagonist), naltrindole (a selective delta-opioid receptor antagonist), and beta-funaltrexamine (a selective mu-opioid receptor antagonist) in a dose-dependent manner, but not by the selective kappa-opioid receptor antagonist norbinaltorphimine. Since it is unlikely that nociceptin acts by direct binding to opioid receptors, these results suggest a possible interaction between the nociceptin/ORL1 and opioid systems in the dorsal horn of the rat spinal cord. |
| |
Keywords: | Antinociception Intrathecal Nociceptin/orphanin FQ Opioid-receptor-like receptor Opioid |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|