Effect of hypophysectomy on hypothalamic growth hormone-releasing factor content and release in the rat.
Endocrinology
; 120(3): 1079-82, 1987 Mar.
Article
em En
| MEDLINE
| ID: mdl-3100283
ABSTRACT
The possible regulation of hypothalamic GH-releasing factor (GRF) by GH was studied in untreated and GH-treated hypophysectomized rats by measurement of rat hypothalamic GRF content and release in vitro with a specific GRF RIA. Two weeks after hypophysectomy, animals not receiving hormone replacement showed a marked reduction in hypothalamic GRF content (to 28% of sham-operated control values; P less than 0.001). Replacement therapy with T4, cortisone, and testosterone for 9 days did not correct the decrease in hypothalamic GRF content in hypophysectomized rats, though the addition of GH therapy partially restored GRF levels (to 55% of control values; P less than 0.001). GRF release from incubated mediobasal hypothalamic fragments of hypophysectomized rats was decreased both basally and in response to 30 mM K+. This defect was completely corrected by prior GH treatment. The results suggest an impairment of GRF synthesis and release in the presence of GH deficiency.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hormônio Liberador de Hormônio do Crescimento
/
Hipofisectomia
/
Hipotálamo
Limite:
Animals
Idioma:
En
Revista:
Endocrinology
Ano de publicação:
1987
Tipo de documento:
Article