Assessment for the Role of Serotonin Receptor Subtype 3 for the Analgesic Action of Morphine at the Spinal Level.
10.3344/kjp.2005.18.2.113
- Author:
Myung Ha YOON
1
;
Hong Buem BAE
;
Jeong Il CHOI
;
Seok Jae KIM
;
Chang Mo KIM
;
Sung Tae JEONG
;
Kwang Su KIM
;
Won Jong JIN
;
Jong Pil KIM
;
Jong Sik KIM
;
Se Yeol KIM
;
Chang Young JEONG
Author Information
1. Department of Anesthesiology and Pain Medicine, Medical School, Chonnam National University, Gwangju, Korea. mhyoon@chonnam.ac.kr
- Publication Type:Original Article
- Keywords:
analgesia;
formalin test;
morphine;
rat;
serotonin 3 receptor;
spinal cord
- MeSH:
Analgesia;
Animals;
Catheters;
Formaldehyde;
Humans;
Male;
Morphine*;
Nausea;
Nociception;
Pain Measurement;
Rats;
Rats, Sprague-Dawley;
Receptors, Serotonin, 5-HT3;
Serotonin*;
Spinal Cord;
Vomiting
- From:The Korean Journal of Pain
2005;18(2):113-117
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Serotonin 3 receptor is involved in the modulation of nociceptive transmission in the spinal cord. The serotonin 3 receptor antagonist has been used for the management of opioid-induced nausea and vomiting. The aim of this study was to examine whether the analgesic effect of morphine is antagonized by serotonin 3 receptor antagonists at the spinal level. METHODS: Rats were implanted with lumbar intrathecal catheters. For nociception, a formalin solution (5%, 50microliter) was injected into the hind paw of male Sprague-Dawley rats. To determine whether the effect of intrathecal morphine was mediated via serotonin 3 receptors, serotonin 3 receptor antagonists were intrathecally administered 10 min prior to the morphine delivery. Following the formalin injection, formalin-induced nociceptive behavior (flinching response) was observed for 60 min. RESULTS: Intrathecal morphine produced a dose-dependent suppression of the flinches in both phases during the formalin test. The analgesic action of morphine was not reversed by serotonin 3 receptor antagonists (LY-278, 584, ondansetron), which had little per se effect on the formalin-induced nociception. CONCLUSIONS: Spinal serotonin 3 receptors may not be involved in the analgesia of morphine on a nociceptive state evoked by a formalin stimulus.
