Phencyclidine and dizocilpine modulate dopamine release from rat nucleus accumbens via sigma receptors.
Eur J Pharmacol
; 386(2-3): 145-53, 1999 Dec 15.
Article
em En
| MEDLINE
| ID: mdl-10618464
ABSTRACT
Phencyclidine (PCP) binds to many sites in brain, including PCP receptors located within the N-methyl-D-aspartate (NMDA) receptor-operated cation channel and sigma (sigma) receptors. In this study, we compare mechanisms by which PCP, dizocilpine (MK-801), the prototypical sigma receptor agonist (+)-pentazocine, and the proposed endogenous sigma receptor ligand neuropeptide Y regulate potassium (K(+))-stimulated [3H]dopamine release from slices of rat nucleus accumbens. (+)-Pentazocine inhibits K(+)-stimulated [3H]dopamine release, and neuropeptide Y enhances it. Both effects are blocked by sigma(1) and neuropeptide Y receptor antagonists, suggesting possible inverse agonism at a subpopulation of sigma/neuropeptide Y receptors. In contrast, PCP and MK-801 both enhance K(+)-stimulated [3H]dopamine release via sigma(1) and sigma(2) receptor subtypes, as demonstrated by antagonist sensitivity. Regulation of release by both (+)-pentazocine and neuropeptide Y persists in the presence of tetrodotoxin suggests that the sigma/neuropeptide Y receptors mediating the modulation are located presynaptically on dopaminergic nerve terminals, but tetrodotoxin eliminates regulation by PCP and MK-801, suggesting that receptors mediating their effects are located upstream from dopaminergic nerve terminals.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenciclidina
/
Dopamina
/
Maleato de Dizocilpina
/
Receptores sigma
/
Núcleo Accumbens
Limite:
Animals
Idioma:
En
Ano de publicação:
1999
Tipo de documento:
Article