Effect of platelet-activating factor on hypothalamic and hypophyseal pro-opiomelanocortin-related peptides and hypothalamo-pituitary-adrenal axis in the rat.
Eur J Pharmacol
; 177(3): 145-53, 1990 Feb 27.
Article
em En
| MEDLINE
| ID: mdl-2155805
ABSTRACT
To examine the effect of platelet-activating factor (PAF-acether) on pro-opiomelanocortin (POMC)-related peptides and on the hypothalamo-pituitary-adrenal axis, we administered PAF-acether and BN 52021, a selective PAF-acether antagonist, to freely moving rats. Minipumps loaded with either PAF-acether (30 micrograms/kg) or the vehicle alone were connected to the jugular vein for 7 days and positioned under the back skin of rats. A group of animals treated with PAF-acether also received 15 mg/kg of BN 52021 orally twice a day. In vivo treatment with PAF-acether alone or in association with BN 52021 did not affect the hypothalamic concentrations of corticotropin-releasing factor (CRF), alpha-melanocyte-stimulating hormone (alpha-MSH) and beta-endorphin. Using a perifusion system for rat hypothalamic slices, we did not observe any effect of PAF-acether on spontaneous or potassium-induced release of alpha-MSH in vitro. In addition, treatment of rats with PAF-acether alone or in association with BN 52021 did not modify the alpha-MSH or beta-endorphin concentration in the neurointermediate lobe of the pituitary. In contrast, in vivo administration of PAF-acether caused a significant reduction of ACTH concentration in the anterior lobe of the pituitary and a marked decrease in the corticosterone level in plasma and adrenal glands. The inhibitory effect of PAF-acether was reversed by concomitant administration of BN 52021. The ineffectiveness of PAF-acether to modulate in vitro ACTH release from perifused anterior pituitary fragments ruled out a direct effect of PAF-acether on corticotrophs. These findings support the view that PAF-acether exerts a specific inhibitory effect on the hypothalamo-pituitary-adrenal axis.
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Base de dados:
MEDLINE
Assunto principal:
Peptídeos
/
Sistema Hipófise-Suprarrenal
/
Neuro-Hipófise
/
Pró-Opiomelanocortina
/
Fator de Ativação de Plaquetas
/
Diterpenos
/
Sistema Hipotálamo-Hipofisário
/
Hipotálamo
Idioma:
En
Revista:
Eur J Pharmacol
Ano de publicação:
1990
Tipo de documento:
Article
País de afiliação:
França