Androgen modulation of luteinizing hormone secretion by female rat gonadotropes

Judith L Turgeon, Dennis W. Waring

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

In the female, androgens can have negative and positive actions in the regulation of LH, but it is not clear how they may function during the reproductive cycle. Toward resolving these potentially conflicting roles for androgen, we used an in vitro model of preovulatory gonadotropes to examine the effect of proestrous levels of testosterone (1.7 nM) or dihydrotestosterone (DHT; 0.7 nM) on LH secretion in response to pulsatile GnRH (1 nM) or elevated extracellular K+ (54 mM). For female rat pituitary cells cultured in 17β-estradiol (E2)-containing medium, androgen treatment for 16 h, but not for 4 h, inhibited the LH secretory response to a pulse of either GnRH or K+ by about 60% and suppressed the acute augmentation action of 2O nM progesterone on GnRH- or K+-induced LH secretion. In the absence of E2, DHT also decreased LH secretion induced by a pulse of GnRH. DHT's suppressive effect on progesterone could be partially overcome with increased progesterone (200 nM) or by removal of DHT during progesterone exposure. For pituitary cells transfected with a reporter plasmid containing three progesterone response elements, DHT only partially suppressed progesterone- stimulated transcriptional activity. The positive action of androgen (16 h) on LH secretion was elicited by multiple GnRH pulses with a latency of about 2 h after the first pulse; this facilitatory action of androgen did not require an E2 background and, therefore, is distinct from GnRH self priming. In summary, these data demonstrate both facilitatory and inhibitory actions of androgen on LH secretion function in female gonadotropes in vitro in the absence or presence of E2; these actions occur with a time course suggestive of a role for androgen in shaping the preovulatory LH surge. Androgen also markedly suppresses progesterone augmentation of stimulated LH secretion, which could be due in part to interference with the trans-activation function of the progesterone receptor.

Original languageEnglish (US)
Pages (from-to)1767-1774
Number of pages8
JournalEndocrinology
Volume140
Issue number4
StatePublished - 1999

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Luteinizing Hormone
Androgens
Progesterone
Gonadotropin-Releasing Hormone
Dihydrotestosterone
Response Elements
Progesterone Receptors
Testosterone
Estradiol
Cultured Cells
Plasmids

ASJC Scopus subject areas

  • Endocrinology
  • Endocrinology, Diabetes and Metabolism

Cite this

Androgen modulation of luteinizing hormone secretion by female rat gonadotropes. / Turgeon, Judith L; Waring, Dennis W.

In: Endocrinology, Vol. 140, No. 4, 1999, p. 1767-1774.

Research output: Contribution to journalArticle

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