Thyroid hormones regulate the formation of inositol phosphate in response to thyrotropin-releasing hormone in rat anterior pituitaries.
Neuropeptides
; 21(1): 49-53, 1992 Jan.
Article
en En
| MEDLINE
| ID: mdl-1738433
ABSTRACT
The effects of thyroid hormones on TSH secretion and inositol phospholipid hydrolysis in response to thyrotropin-releasing hormone (TRH) in rat anterior pituitaries were examined. Experimental hypothyroidism caused a significant increase in [3H]inositol phosphate ([3H]IP) formation in response to TRH in rat anterior pituitaries with a concomitant elevation of blood TSH. In contrast, administration of thyroxine (T4) to hypothyroid rats resulted in a complete restoration of blood TSH and TRH-stimulated [3H]IP formation to the euthyroid control value. Furthermore, in vitro pre-treatment of anterior pituitaries with triiodothyronine (T3) produced a dose-dependent decrease in both TSH secretion and the formation of [3H]IP in response to TRH. These results indicate that thyroid hormones regulate TRH receptor-linked inositol phospholipid hydrolysis in the rat anterior pituitary, suggesting that negative feedback action of thyroid hormone occurs at post receptor event in the rat anterior pituitary, which may, to a certain extent, be responsible for the underlying mechanism of T3 inhibition of TSH secretion.
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Banco de datos:
MEDLINE
Asunto principal:
Adenohipófisis
/
Hormonas Tiroideas
/
Tirotropina
/
Fosfatos de Inositol
Límite:
Animals
Idioma:
En
Año:
1992
Tipo del documento:
Article