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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Hypothalamic-pituitary-adrenal axis up-regulation in rats submitted to pituitary stalk compression

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Autor(es):
Elias, P. C. ; Elias, L. L. ; Castro, M. ; Antunes-Rodrigues, J. [4] ; Moreira, A. C.
Número total de Autores: 5
Tipo de documento: Artigo Científico
Fonte: Journal of Endocrinology; v. 180, n. 2, p. 297-302, Feb. 2004.
Área do conhecimento: Ciências Biológicas - Fisiologia
Assunto(s):Hipófise   Hipotálamo   Hormônio adrenocorticotrópico
Resumo

The present study investigated the hypothalamic-pituitary-adrenal (HPA) axis activity in response to stress in adult male rats submitted to pituitary stalk compression (PSC) or sham operation. Animals received water or oral salt loading (2% NaCl) for one or eight days before the day of the experiment. On the 14th day post-surgery rats were killed under basal conditions or after 15 min immobilization stress. In the PSC group urine output increased significantly and plasma vasopressin (AVP) levels failed to respond to osmotic stimuli. Short-term salt load induced a significant increase in AVP levels in the sham-operated group. The PSC group presented higher adrenocorticotrophin (ACTH) and corticosterone levels compared with sham-operated rats, both in water intake and salt load conditions. Immobilization stress induced a similar increase in plasma ACTH and corticosterone concentrations in sham-operated and PSC groups under water intake. However, long-term salt load blunted the ACTH and corticosterone responses to immobilization stress in sham-operated rats. PSC rats submitted to short- and long-term salt loading presented no changes in ACTH and corticosterone levels after immobilization. Immobilization stress caused neither AVP responses nor plasma osmolality changes in sham and PSC groups. There was no difference in median eminence AVP content among all groups. In conclusion, the high ACTH and corticosterone levels found in PSC rats under water intake and salt loading conditions suggest an up-regulation of the HPA axis, with a preserved adaptive mechanism to chronic stress. (AU)

Processo FAPESP: 01/04638-2 - Diabetes insípido, clínico e experimental: aspectos moleculares e funcionais na regulação do eixo hipotálamo-hipófise-adrenal
Beneficiário:Paula Condé Lamparelli Elias
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 98/06529-1 - Avaliação do eixo hipotálamo-hipófise-adrenal em ratos submetidos à neurohipofisectomia funcional: papel da vasopressina central
Beneficiário:Paula Condé Lamparelli Elias
Linha de fomento: Bolsas no Brasil - Doutorado