Alpha 2-adrenoceptor modulates the release of acetylcholine from the rostral ventrolateral medulla in response to morphine.
Biol Pharm Bull
; 26(11): 1548-51, 2003 Nov.
Article
en En
| MEDLINE
| ID: mdl-14600399
The present study examined the role of the noradrenergic system in the modulation of acetylcholine (ACh) release in the rostral ventrolateral medulla (RVLM) using in vivo microdialysis of morphine. The basal level of ACh was 325.0 +/- 21.1 fmol/20 microl/15 min in the presence of neostigmine (10 microM). Intraperitoneal (i.p.) administration of 5 and 10 mg/kg morphine significantly increased ACh release by the RVLM. This enhancement was reversed by naloxone (1 mg/kg, i.p.). In addition, pretreatment with yohimbine (0.5 mg/kg, i.p.) or prazosin (0.2 mg/kg, i.p.) attenuated the systemic morphine-induced release of ACh in the RVLM. However, propranolol (0.2 mg/kg, i.p.) did not affect the morphine-induced ACh release. The addition of morphine (10(-4) M) to the perfusion medium increased the ACh release by 72.4% of the predrug values. The increased ACh release induced by local application of morphine was attenuated by pretreatment with yohimbine, but not prazosin. These findings suggest that morphine exerts an indirect stimulatory effect on the release of ACh by the RVLM and that the morphine-induced increase in ACh release is modulated by alpha2-adrenoceptors in freely moving rats.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Bulbo Raquídeo
/
Acetilcolina
/
Receptores Adrenérgicos alfa 2
/
Morfina
Límite:
Animals
Idioma:
En
Revista:
Biol Pharm Bull
Asunto de la revista:
BIOQUIMICA
/
FARMACOLOGIA
Año:
2003
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Japón