Expression of corticotropin-releasing hormone type 1 receptor in paraventricular nucleus after acute stress.
Neuroendocrinology
; 73(5): 293-301, 2001 May.
Article
en En
| MEDLINE
| ID: mdl-11399902
We have previously proposed the existence of ultrashort loop-positive feedback regulation of corticotropin-releasing hormone (CRH) in the hypothalamus. To gain a better understanding of this effect, we performed double-label in situ hybridization to identify the neurons in the paraventricular nucleus (PVN) that express CRH type 1 receptor (CRH-R1) following stress. We also conducted immunohistochemistry to determine whether CRH-R1 mRNA was translated to CRH-R1 protein in the PVN. Thirty-minute restraint stress given to male Wistar rats increased c-fos mRNA expression primarily in the CRH-producing neurons of the parvocellular PVN. Small numbers of vasopressin and oxytoxin-producing cells were also labeled by c-fos probes. Approximately 70% of CRH-R1 positive neurons exhibited CRH mRNA 2 h after the beginning of stress, while only a small percentage of the vasopressin and oxytocin-producing cells coexpressed CRH-R1 mRNA. CRH-R1 immunoreactivity, which was detected in the perikarya and fibers of PVN neurons, appeared to increase in response to stress, though this was not statistically significant. Pretreatment with a selective CRH-R1 antagonist, CP-154,526, significantly attenuated stress-induced corticotropin (ACTH) secretion as well as c-fos mRNA expression in the PVN. These results demonstrate that acute stress increases neuronal activation and CRH-R1 mRNA expression primarily in CRH-producing neurons of the parvocellular PVN, that CRH-R1 message is translated to CRH-R1 protein, and that PVN neurons are activated at least in part through CRH-R1 under acute stress. The data further support the possibility of feedback regulation of CRH itself in CRH-producing neurons.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Núcleo Hipotalámico Paraventricular
/
Estrés Fisiológico
/
Expresión Génica
/
Receptores de Hormona Liberadora de Corticotropina
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Neuroendocrinology
Año:
2001
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Suiza