Effects of testosterone on hormonal content and calcium-dependent basal secretion in female rat pituitary cells

• Published in: The Journal of steroid biochemistry and molecular biology Vol. 103; no. 2; pp. 149 - 157
• Main Authors: Weiss, Juergen M., Stojilkovic, Stanko S., Diedrich, Klaus, Ortmann, Olaf
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-02-2007; Elsevier Science
• Subjects: 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester - pharmacology; Animals; Anterior pituitary cells; Basal release; Biological and medical sciences; Calcium - physiology; Calcium Signaling - drug effects; Calcium signalling; Cells, Cultured; Female; Fundamental and applied biological sciences. Psychology; General aspects. Hormone interactions. Hormone actions on several organ systems. Adaptive reactions; Growth Hormone - analysis; Growth Hormone - secretion; Hormonal content; Luteinizing Hormone - analysis; Luteinizing Hormone - secretion; Pituitary Gland - chemistry; Pituitary Gland - drug effects; Pituitary Gland - secretion; Pituitary Hormones - analysis; Pituitary Hormones - secretion; Prolactin - analysis; Prolactin - secretion; Rats; Rats, Sprague-Dawley; Testosterone; Testosterone - pharmacology; Vertebrates: endocrinology; Calcium signalling; Testosterone; Basal release; Anterior pituitary cells; Hormonal content; Endocrine gland; Androgen; Calcium; Rat; Rodentia; Signalling; Endocrine secretion; Adenohypophysis; Vertebrata; Mammalia; Female; Pituitary gland; Testicular hormone; Sex steroid hormone
• ISSN: 0960-0760; 1879-1220
• DOI: 10.1016/j.jsbmb.2006.09.038

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 (1
pM to 10
nM) was added for 48
h. 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
50s 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.