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Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.

The first portion of this paper is devoted to an overview of the normal function of the hypothalamo-pituitary-thyroid axis. This section emphasizes areas of current research interest and it identifies several sites and mechanisms that are potentially important interfaces with toxins or toxic mechani...

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Detalles Bibliográficos
Autores principales: Hedge, G A, Wright, K C, Judd, A
Formato: Texto
Lenguaje:English
Publicado: 1981
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1568447/
https://www.ncbi.nlm.nih.gov/pubmed/6113137
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author Hedge, G A
Wright, K C
Judd, A
author_facet Hedge, G A
Wright, K C
Judd, A
author_sort Hedge, G A
collection PubMed
description The first portion of this paper is devoted to an overview of the normal function of the hypothalamo-pituitary-thyroid axis. This section emphasizes areas of current research interest and it identifies several sites and mechanisms that are potentially important interfaces with toxins or toxic mechanisms. We then describe an in vitro technique for the continuous superfusion of enzymatically dispersed pituitary cells; this approach is particularly valuable in studying the dynamics of the TSH responses to the factors known (or suspected) to regulate TSH secretion in vivo. Using this technique, we have found that 10(-5)M prostaglandin (PG)I2 stimulates TSH secretion without altering the response to TRH (10(-8)M), and that this stimulation is not due to its rapid conversion to 6-keto PGF1 alpha. In contrast PGs of the E series (PGE1 and PGE2, 10(-5)M) increase responsiveness to TRH but have no effect alone. We found no effects of any of the other prostanoids tested (PGs A2, B2, F1 alpha, F2 alpha, thromboxanes A2 and B2, and the endoperoxide analog, U-44069. Somatostain (10(-9)M inhibits TRH-induced TSH secretion, but does not alter the responsiveness to PGI2. These findings suggest that somatostatin blocks TSH secretion at a point that is functionally prior to the involvement of the PGs, and perhaps does so by blocking synthesis or limiting availability of selected PGs.
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spelling pubmed-15684472006-09-19 Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis. Hedge, G A Wright, K C Judd, A Environ Health Perspect Research Article The first portion of this paper is devoted to an overview of the normal function of the hypothalamo-pituitary-thyroid axis. This section emphasizes areas of current research interest and it identifies several sites and mechanisms that are potentially important interfaces with toxins or toxic mechanisms. We then describe an in vitro technique for the continuous superfusion of enzymatically dispersed pituitary cells; this approach is particularly valuable in studying the dynamics of the TSH responses to the factors known (or suspected) to regulate TSH secretion in vivo. Using this technique, we have found that 10(-5)M prostaglandin (PG)I2 stimulates TSH secretion without altering the response to TRH (10(-8)M), and that this stimulation is not due to its rapid conversion to 6-keto PGF1 alpha. In contrast PGs of the E series (PGE1 and PGE2, 10(-5)M) increase responsiveness to TRH but have no effect alone. We found no effects of any of the other prostanoids tested (PGs A2, B2, F1 alpha, F2 alpha, thromboxanes A2 and B2, and the endoperoxide analog, U-44069. Somatostain (10(-9)M inhibits TRH-induced TSH secretion, but does not alter the responsiveness to PGI2. These findings suggest that somatostatin blocks TSH secretion at a point that is functionally prior to the involvement of the PGs, and perhaps does so by blocking synthesis or limiting availability of selected PGs. 1981-04 /pmc/articles/PMC1568447/ /pubmed/6113137 Text en
spellingShingle Research Article
Hedge, G A
Wright, K C
Judd, A
Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
title Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
title_full Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
title_fullStr Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
title_full_unstemmed Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
title_short Factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
title_sort factors modulating the secretion of thyrotropin and other hormones of the thyroid axis.
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1568447/
https://www.ncbi.nlm.nih.gov/pubmed/6113137
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