A comparison of the biological activities of authentic rat GRF(1-43)OH with the analogue rat GRF(1-29)NH2.
Can J Physiol Pharmacol
; 69(2): 181-4, 1991 Feb.
Article
em En
| MEDLINE
| ID: mdl-1829020
ABSTRACT
The purpose of this study was to characterize the biological activity of the synthetic rat growth hormone releasing factor analogue rGRF(1-29)NH2 and to compare its action on growth hormone (GH) release to that of authentic rGRF(1-43)OH. We first compared the concentration-response characteristics of the two peptides in static incubation, and then examined the reversibility and repeatability of the GH response in a perifusion system. Authentic rGRF(1-43)OH was significantly more potent in static incubation (EC50 = 3 x 10(-11) M) than the analogue (5 x 10(-11) M), whereas the reverse held true in perifusion. The shapes of the GH responses were similar for both peptides in the perifusion system. However, while the GH response to authentic rGRF was repeatable, the prior administration of rGRF(1-29)NH2 significantly reduced (greater than 50%) the GH response to the subsequent administration of either rGRF(1-29)NH2 or rGRF(1-43)OH. Thus authentic rGRF and the synthetic fragment may have different actions at the level of the GRF receptor or at a postreceptor (second messenger) step.
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Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Hormônio Liberador de Hormônio do Crescimento
Limite:
Animals
Idioma:
En
Revista:
Can J Physiol Pharmacol
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
Canadá