Systemic morphine produce antinociception mediated by spinal 5-HT7, but not 5-HT1A and 5-HT2 receptors in the spinal cord.
Br J Pharmacol
; 149(5): 498-505, 2006 Nov.
Article
en En
| MEDLINE
| ID: mdl-16921395
ABSTRACT
BACKGROUND AND PURPOSE:
The serotonergic system within the spinal cord have been proposed to play an important role in the analgesic effects of systemic morphine. Currently, seven groups of 5-HT receptors (5-HT1-7) have been characterized. One of the most recently identified subtypes of 5 HT receptor is the 5-HT7 receptor. We aimed to examine the role of spinal 5-HT7 receptors in the antinociceptive effects of systemic morphine. EXPERIMENTALAPPROACH:
The involvement of spinal 5-HT7 receptor in systemic morphine antinociception was compared to that of the 5-HT1A and 5-HT2 receptors by using the selective 5-HT7 receptor antagonist, SB-269970, the selective 5-HT1A receptor antagonist, WAY 100635, the selective 5-HT2 antagonist ketanserin as well as the non-selective 5-HT1,2,7 receptor antagonist, metergoline. Nociception was evaluated by the radiant heat tail-flick test. KEYRESULTS:
I.t. administration of SB-269970 (10 microg) and metergoline (20 microg) completely blocked the s.c. administered morphine-induced (1, 3, 5 and 10 mg kg(-1)) antinociception in a time-dependent manner. Additionally, i.t. administration of SB-269970 (1, 3, 10 and 20 microg) and metergoline (1, 5, 10 and 20 microg) dose dependently inhibited the antinociceptive effects of a maximal dose of morphine (10 mg kg(-1), s.c.). I.t. administration of WAY 100635 (20 microg) or ketanserine (20 microg) did not alter morphine-induced (1, 3, 5 and 10 mg kg(-1), s.c.) antinociception. CONCLUSION AND IMPLICATIONS These findings indicate that the involvement of spinal 5-HT7, but not of 5-HT1A or of 5-HT2 receptors in the antinociceptive effects of systemic morphine.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Dolor
/
Médula Espinal
/
Receptores de Serotonina
/
Morfina
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Br J Pharmacol
Año:
2006
Tipo del documento:
Article
País de afiliación:
Turquía