The secretory activity of the tuberoinfundibular dopaminergic neurons is modulated by the thyroid status in the adult rat: consequence on prolactin secretion

Details

Serval ID
serval:BIB_A3E69D9190B6
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The secretory activity of the tuberoinfundibular dopaminergic neurons is modulated by the thyroid status in the adult rat: consequence on prolactin secretion
Journal
Neuroendocrinology
Author(s)
Reymond  M. J., Benotto  W., Lemarchand-Beraud  T.
ISSN
0028-3835
Publication state
Published
Issued date
06/1987
Peer-reviewed
Oui
Volume
46
Number
1
Pages
62-8
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jun
Abstract
An influence of thyroid status on the secretory activity of hypothalamic dopaminergic neurons was observed in adult rats and its involvement in the regulation of prolactin (PRL) secretion was examined. The secretory activity of the tuberoinfundibular dopaminergic (TIDA) neurons was evaluated by measurement of dopamine (DA) biosynthesis in the neurons and DA release into hypophysial portal blood. The accumulation of DA and PRL in the adenohypophysis as well as PRL concentration in plasma were also estimated, and the various parameters were studied in thyroidectomized (TX), sham TX, TX rats treated for 7 days with thyroxine (T4; 20 micrograms/kg body weight daily) as well as in intact rats treated similarly with T4. An enhanced secretory activity of the TIDA neurons was observed in TX compared to sham TX rats, as attested by an increased synthesis of DA in the neurons, a greater concentration of DA in hypophysial portal plasma as well as an augmented accumulation of DA in the adenohypophysis. In the same animals, PRL was reduced in the adenohypophysis and in plasma, reflecting a blunted secretion of PRL in severe hypothyroidism. Treatment of TX rats with T4 for 7 days abolished all effects observed in TX rats, DA synthesis in TIDA neurons of TX rats treated with T4 being even less than in neurons of sham TX animals. A similar treatment with T4 administered to intact rats did not affect the secretory activity of the TIDA neurons nor the secretion of PRL.(ABSTRACT TRUNCATED AT 250 WORDS)
Keywords
Animals Dihydroxyphenylalanine/metabolism Dopamine/*metabolism Male Median Eminence/drug effects/*metabolism Neural Pathways/drug effects/metabolism Pituitary Gland, Anterior/*metabolism Prolactin/*metabolism Rats Rats, Inbred Strains Thyroid Gland/metabolism/*physiology Thyroid Hormones/blood Thyroidectomy Thyrotropin/metabolism Thyroxine/pharmacology
Pubmed
Web of science
Create date
11/02/2008 14:12
Last modification date
20/08/2019 15:09
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