Cholecystokinin octapeptide (CCK-8) antagonizes morphine analgesia in nucleus accumbens of the rat via the CCK-B receptor.
Brain Res
; 657(1-2): 159-64, 1994 Sep 19.
Article
em En
| MEDLINE
| ID: mdl-7820614
ABSTRACT
The analgesic effect of systemic morphine (4 mg/kg, s.c.) was antagonized in a dose-dependent manner by cholecystokinin octapeptide (CCK-8) (0.1-0.5 ng) administered bilaterally to the nucleus accumbens of the rat. This effect of CCK-8 could be reversed by devazepide, a CCK-A receptor antagonist, at 50 ng and 200 ng and by L-365,260, a CCK-B receptor antagonist, at 5 ng administered bilaterally to the nucleus accumbens. A marked potentiation of morphine analgesia was achieved by intra-nucleus accumbens injection of 200 ng devazepide or 5 ng L-365,260. Since the effect of L-365,260 in antagonizing the anti-opioid effect of CCK-8 in the nucleus accumbens is 40 times more potent than devazepide, it is suggested that the anti-opioid effect of CCK-8 is mediated by CCK-B receptors. In conclusion, nucleus accumbens is a strategic site where CCK-8 exerts an anti-opioid activity, most probably via the CCK-B receptors.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Fenilureia
/
Sincalida
/
Receptores da Colecistocinina
/
Morfina
/
Núcleo Accumbens
Limite:
Animals
Idioma:
En
Ano de publicação:
1994
Tipo de documento:
Article