Different apparent modes of inhibition of alpha2A-adrenoceptor by alpha2-adrenoceptor antagonists.
Eur J Pharmacol
; 335(1): 99-105, 1997 Sep 17.
Article
em En
| MEDLINE
| ID: mdl-9371550
ABSTRACT
The inhibition of alpha2A-adrenoceptor-mediated Ca2+ elevation by alpha2-adrenoceptor antagonists was measured in HEL human erythroleukemia cells. The antagonists could be divided in two classes those that displayed surmountable inhibition (right-shift of the agonist dose-response curve), and those that displayed different degrees of insurmountable inhibition (depression of the maximum signal and a possible right-shift of the agonist dose-response curve). The degree of surmountability of the inhibition correlated well with the measured antagonist dissociation rates, suggesting that the hypothesis of the antagonist dissociation rate governing the mode of inhibition of fast responses, holds true. HEL cells thus provide a useful model system for the investigation of physiological consequences of different dissociation rates. Also, the dissociation rates of antagonists not available in radiolabelled form can be predicted from the functional data. The data stresses the importance of measurement of kinetic parameters of the drug-receptor interaction in addition to the equilibrium binding constants.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Antagonistas Adrenérgicos alfa
/
Antagonistas de Receptores Adrenérgicos alfa 2
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Eur J Pharmacol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Suécia