Differential responses of the hypothalamo-pituitary-adrenocortical axis to acute restraint stress in Hatano high- and low-avoidance rats.
J Endocrinol
; 181(3): 515-20, 2004 Jun.
Article
em En
| MEDLINE
| ID: mdl-15171699
The high- and low-avoidance animal (HAA and LAA respectively) strains of Hatano rats were originally selected and bred from Sprague-Dawley rats for their performance in the shuttle-box task. The present study focused on the activity of the hypothalamo-pituitary-adrenocortical (HPA) axis of HAA and LAA rats in response to restraint stress. The restraint stress induced an elevation in plasma concentrations of ACTH, prolactin, corticosterone and progesterone. Peak levels of plasma ACTH during stress conditions were significantly higher in HAA rats than in LAA rats, while peak levels of prolactin were significantly lower in HAA rats than in LAA rats. Under stress conditions, ACTH and prolactin synthesis in the anterior pituitary glands was significantly higher in HAA rats compared with LAA rats. The peak plasma concentrations of corticosterone, during restraint stress, were significantly higher in LAA rats compared with HAA rats. These results indicate that the response of the hypothalamo-pituitary axis to acute restraint stress is greater in HAA rats than in LAA rats, whereas the ACTH-induced adrenal response of corticosterone release is higher in LAA rats than in HAA rats. On the other hand, prolactin secretory activity is higher in LAA rats compared with HAA rats. These differences in endocrine responses to stress may be involved in the regulation of the avoidance responses in the shuttle-box task.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sistema Hipófise-Suprarrenal
/
Estresse Psicológico
/
Sistema Hipotálamo-Hipofisário
Limite:
Animals
Idioma:
En
Revista:
J Endocrinol
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Japão
País de publicação:
Reino Unido