Perinatal thiouracil exposure depresses corticotropin-releasing factor activity in 15 day old rats.

Medical University of Ohio at Toledo, Toledo, Ohio, United States
Hormone and Metabolic Research (Impact Factor: 2.12). 11/1983; 15(10):488-90. DOI: 10.1055/s-2007-1018766
Source: PubMed


Although previous in vivo studies have shown thiouracil to delay maturation of the hypothalamus-pituitary-adrenal (HPA) axis response to stress, the nature of the developmental deficit was not determined. By in vitro methods we determined which HPA components are influenced by thiouracil-induced hypothyroidism in 15 day old rats. Our results indicate that adrenal response to ACTH stimulation and adenohypophysial ACTH content were not significantly modified by thiouracil exposure. On the other hand, the corticotropin-releasing factor-like activity of median eminence extracts was severely depressed by thiouracil-induced hypothyroidism. Thus, the delayed maturation of functional capacity of the central nervous system caused by hypothyroidism includes synthesis of biologically active corticotropin-releasing factor.

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    ABSTRACT: Depression of thyroid status with thiouracil has been shown to delay the response of the hypothalamus-pituitary-adrenal axis to stress in young rats. In vivo and in vitro bioassay studies have indicated that the hypothalamus is the main site of axis alteration in 15 day old animals. The present study has found a significantly depressed hypothalamic content of immunoassayable corticotropin-releasing factor (CRF) in thiouracil treated young rats.
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