Labelling of rat brain beta-adrenoceptors: (3H)CGP-12177 or (125I)iodocyanopindolol?
J Recept Res
; 12(3): 369-87, 1992.
Article
em En
| MEDLINE
| ID: mdl-1354747
ABSTRACT
Binding of (125I)iodocyanopindolol (ICYP) and (3H)CGP-12177 to rat brain homogenates was characterized and compared. ICYP was shown to bind to both beta-adrenergic and serotonin1B (5HT1B) receptors whereas (3H)CGP-12177 only labelled the first ones. The addition of 10 microM serotonin (5HT) prevented ICYP binding to 5HT receptors and under these experimental conditions both ligands labelled a similar total number of beta-adrenoceptors in the different rat brain regions. ICYP displayed a higher affinity for cerebellar (mainly beta 2-subtype) than for cerebral cortex beta-adrenoceptors (mainly beta 1-subtype) suggesting a subtype selectivity. A multiple displacement binding approach using CGP-20712A, a beta 1-subtype ligand, as competitor revealed a 2.6 fold selectivity of ICYP for the beta 2-adrenoceptor subtype. On the other hand, (3H)CGP-12177 binds only to beta-adrenoceptors and is not subtype selective in the rat brain homogenate. Considering both its high specificity and its lack of subtype selectivity (3H)CGP-12177 seems to be a more suitable ligand than ICYP to non-selectively label beta-adrenoceptors in rat brain.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pindolol
/
Propanolaminas
/
Córtex Cerebral
/
Antagonistas Adrenérgicos beta
/
Hipocampo
Limite:
Animals
Idioma:
En
Revista:
J Recept Res
Ano de publicação:
1992
Tipo de documento:
Article
País de afiliação:
França