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Effects of testosterone on hormonal content and calcium-dependent basal secretion in female rat pituitary cells.
- Source :
-
The Journal of steroid biochemistry and molecular biology [J Steroid Biochem Mol Biol] 2007 Feb; Vol. 103 (2), pp. 149-57. Date of Electronic Publication: 2006 Nov 02. - Publication Year :
- 2007
-
Abstract
- In vivo and in vitro effects of elevated androgens on agonist-induced gonadotropin secretion have been addressed previously. Here we investigated the effects of testosterone on hormonal content and basal (in the absence of agonists) hormone release in pituitary lactotrophs, somatotrophs and gonadotrophs from female rats. Furthermore we tested the hypothesis that testosterone action is dependent on the pattern of spontaneous and Bay K 8644 (a L-type calcium channel agonist) -induced calcium signalling. Mixed anterior pituitary cells were cultured in steroid containing or depleted media, and testosterone (1pM to 10nM) was added for 48h. Cells were studied for their spontaneous and Bay K 8644-induced calcium signalling pattern and total hormone levels (release and hormonal content). In lactotrophs, somatotrophs and gonadotrophs testosterone did not affect the pattern of spontaneous calcium signalling. Bay K 8644-induced calcium signalling and hormone release were not affected by testosterone. In both steroid-depleted and -containing medium, testosterone inhibited prolactin (PRL), luteinizing hormone (LH) and growth hormone (GH) cellular content and release in a dose-dependent manner, with IC(50)s in a sub-nanomolar concentration range. These results indicate that testosterone inhibits basal hormone release from lactotrophs, somatotrophs and gonadotrophs without affecting intracellular calcium signalling. This action of testosterone is not dependent on the presence of other steroid hormones.
- Subjects :
- 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester pharmacology
Animals
Calcium Signaling drug effects
Cells, Cultured
Female
Growth Hormone analysis
Growth Hormone metabolism
Luteinizing Hormone analysis
Luteinizing Hormone metabolism
Pituitary Gland metabolism
Pituitary Hormones metabolism
Prolactin analysis
Prolactin metabolism
Rats
Rats, Sprague-Dawley
Calcium physiology
Pituitary Gland chemistry
Pituitary Gland drug effects
Pituitary Hormones analysis
Testosterone pharmacology
Subjects
Details
- Language :
- English
- ISSN :
- 0960-0760
- Volume :
- 103
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- The Journal of steroid biochemistry and molecular biology
- Publication Type :
- Academic Journal
- Accession number :
- 17084076
- Full Text :
- https://doi.org/10.1016/j.jsbmb.2006.09.038