Roles of Serotonergic and Adrenergic Receptors in the Antinociception of Selective Cyclooxygenase-2 Inhibitor in the Rat Spinal Cord.
10.3344/kjp.2011.24.4.179
- Author:
Hye Jin JEONG
1
;
Seong Heon LEE
;
Soo Young CHO
;
Cha Sup LEE
;
Cheol Won JEONG
;
Myung Ha YOON
;
Woong Mo KIM
Author Information
1. Department of Anesthesiology and Pain Medicine, Chonnam National University Hospital, Gwangju, Korea. kimwm@chonnam.ac.kr
- Publication Type:Original Article
- Keywords:
analgesia;
COX-2 inhibitor;
inflammatory pain;
mechanism;
spinal cord
- MeSH:
Adrenergic Antagonists;
Analgesia;
Animals;
Catheters;
Cyclooxygenase 2;
Cyclooxygenase 2 Inhibitors;
Dihydroergocristine;
Formaldehyde;
Humans;
Male;
Neurotransmitter Agents;
Prazosin;
Prostaglandin-Endoperoxide Synthases;
Rats;
Rats, Sprague-Dawley;
Receptors, Adrenergic;
Spinal Cord;
Thiophenes;
Yohimbine
- From:The Korean Journal of Pain
2011;24(4):179-184
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: The analgesic mechanisms of cyclooxygenase (COX)-2 inhibitors have been explained mainly on the basis of the inhibition of prostaglandin biosynthesis. However, several lines of evidence suggest that their analgesic effects are mediated through serotonergic or adrenergic transmissions. We investigated the roles of these neurotransmitters in the antinociception of a selective COX-2 inhibitor at the spinal level. METHODS: DUP-697, a selective COX-2 inhibitor, was delivered through an intrathecal catheter to male Sprague-Dawley rats to examine its effect on the flinching responses evoked by formalin injection into the hindpaw. Subsequently, the effects of intrathecal pretreatment with dihydroergocristine, prazosin, and yohimbine, which are serotonergic, alpha1 adrenergic and alpha2 adrenergic receptor antagonists, respectively, on the analgesia induced by DUP-697 were assessed. RESULTS: Intrathecal DUP-697 reduced the flinching response evoked by formalin injection during phase 1 and 2. But, intrathecal dihydroergocristine, prazosin, and yohimbine had little effect on the antinociception of intrathecal DUP-697 during both phases of the formalin test. CONCLUSIONS: Intrathecal DUP-697, a selective COX-2 inhibitor, effectively relieved inflammatory pain in rats. Either the serotonergic or adrenergic transmissions might not be involved in the analgesic activity of COX-2 inhibitors at the spinal level.
