Reserpine up-regulation of rat renal cortical beta adrenergic receptors is independent of its effect on the sympathetic nervous system.
J Pharmacol Exp Ther
; 253(3): 913-20, 1990 Jun.
Article
em En
| MEDLINE
| ID: mdl-1972754
ABSTRACT
Experiments were performed to evaluate the mechanism underlying our recent observation that reserpine but not surgical denervation up-regulates rat renal cortical beta adrenergic receptors. The specific binding of [125I]iodocyanopindolol was used to quantitate the beta adrenoceptors. Chronic high-dose guanethidine, which decreased renal tissue and circulating catecholamines to the same extent as reserpine, failed to up-regulate renal beta adrenoceptors, which indicates that the effect of reserpine was not due to changes in the ambient catecholamine concentration. Isoproterenol-stimulated renin secretion, a measure of postsynaptic receptor function, was increased by reserpine but not denervation, which indicates that the failure to observe beta adrenoceptor up-regulation by radioligand binding studies after denervation was not an anomaly caused by loss of presynaptic receptors masking postsynaptic supersensitivity. Reserpine was effective even in denervated kidneys. Up-regulation of renal beta adrenoceptors with reserpine occurred even after destruction of peripheral sympathetic nervous system by a combination of adrenal demedullation and high-dose guanethidine administration. A lower daily dose of reserpine (0.3 mg/kg instead of 0.5 mg/kg), which caused no weight loss, was effective in producing beta adrenoceptor up-regulation. Antagonism of reserpine depletion of nerve terminal norepinephrine by tranylcypromine, a monoamine oxidase inhibitor, did not nullify renal beta adrenoceptor up-regulation. Overall, our results indicate that reserpine up-regulation of renal beta adrenergic receptors is independent of the sympathetic nervous system and possibly is a direct effect.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Reserpina
/
Sistema Nervoso Simpático
/
Receptores Adrenérgicos beta
/
Córtex Renal
Limite:
Animals
Idioma:
En
Revista:
J Pharmacol Exp Ther
Ano de publicação:
1990
Tipo de documento:
Article