Thyrotropin-releasing hormone receptor activation does not elevate intracellular cyclic adenosine 3',5'-monophosphate in cells expressing high levels of receptors.
J Clin Endocrinol Metab
; 79(2): 650-2, 1994 Aug.
Article
em En
| MEDLINE
| ID: mdl-8045988
ABSTRACT
Activation of TRH receptors (TRH-R) stimulates a signal transduction pathway that leads to the formation of two second messenger molecules, inositol 1,4,5-trisphosphate and 1,2-diacylglycerol. It has been suggested that TRH may also cause an elevation of another second messenger, cAMP. As adenovirus-mediated gene transfer allows expression of TRH-R to high levels in a number of cell types, we tested again whether TRH-R activation might elevate intracellular cAMP in these more sensitive cell systems. In five cell lines, including three human lines, infection with a replication defective adenovirus that encodes the mouse TRH-R complementary DNA (AdCMVmTRHR) induced the expression of 0.2-2 million TRH-R/cell. AdCMVmTRHR-infected cells were activated by a maximally effective dose of TRH, and the levels of inositol phosphates and cAMP were measured. TRH stimulated the production of inositol phosphates from 5- to 9-fold in all cell types, but did not elevate cAMP in any cell type. These data confirm that TRH-R activation does not lead to an elevation of intracellular cAMP.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores do Hormônio Liberador da Tireotropina
/
AMP Cíclico
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Clin Endocrinol Metab
Ano de publicação:
1994
Tipo de documento:
Article