Evidence against the "spare" receptor nature of alpha 2-adrenoceptors in hamster white fat cells.
Biochem Int
; 20(4): 779-86, 1990.
Article
em En
| MEDLINE
| ID: mdl-1972326
ABSTRACT
After having established the alpha 2-adrenoceptor nature of the binding sites specifically labeled by the alpha 2-agonist [3H] UK 14304 in hamster adipocytes, two different approaches have been used to determine whether these alpha 2-adrenoceptors were "spare receptors". The first one, consisted to block irreversibly fractions of the receptor population by various concentrations of the alpha 2-antagonist benextramine and determine the relationship between the residual receptor occupancy by UK 14304 and the corresponding magnitude of the cellular inhibitory cyclic AMP response to the alpha 2-adrenergic component of epinephrine under conditions avoiding cyclic AMP breakdown. The second approach was a detailed comparison between alpha 2-receptor occupancy by [3H] UK 14304 and the cyclic AMP inhibitory dose-response curve to this agonist in cells incubated also under conditions avoiding cyclic AMP breakdown. These two experimental approaches clearly showed that the alpha 2-adrenoceptor of hamster adipocytes are not "spare receptors".
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tecido Adiposo
/
Receptores Adrenérgicos alfa
Limite:
Animals
Idioma:
En
Ano de publicação:
1990
Tipo de documento:
Article