|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208
Preovulatory GnRH and LH surges depend on activation of estrogen (E2)-inducible progesterone receptors (PGRs) in the preoptic area (POA). Surges do not occur in males, or in perinatally androgenized females. We sought to determine whether prenatal androgen exposure suppresses basal or E2-induced Pgr mRNA expression or E2-induced LH surges (or both) in adulthood, and whether any such effects may be mediated by androgen receptor activation. We also assessed whether prenatal androgens alter subsequent GnRH pulsatility. Pregnant rats received testosterone or vehicle daily on Embryonic Days 1619. POA-hypothalamic tissues were obtained in adulthood for PgrA and PgrB (PgrA+B) mRNA analysis. Females that had prenatal exposure to testosterone (pT) displayed reduced PgrA+B mRNA levels (P < 0.01) compared with those that had prenatal exposure to vehicle (pV). Additional pregnant animals were treated with vehicle or testosterone, or with 5
-dihydrotestosterone (DHT). In adult ovariectomized offspring, estradiol benzoate produced a 2-fold increase (P < 0.05) in PgrA+B expression in the POA of pV females, but not in pT females or those that had prenatal exposure to DHT (pDHT). Prenatal testosterone and DHT exposure also prevented estradiol benzoate-induced LH surges observed in pV rats. Blood sampling of ovariectomized rats revealed increased LH pulse frequency in pDHT versus pV females (P < 0.05). Our findings support the hypothesis that prenatal androgen receptor activation can contribute to the permanent defeminization of the GnRH neurosecretory system, rendering it incapable of initiating GnRH surges, while accelerating basal GnRH pulse generator activity in adulthood. We propose that the effects of prenatal androgen receptor activation on GnRH neurosecretion are mediated in part via permanent impairment of E2-induced PgrA+B gene expression in the POA.
androgen receptor, gene regulation, gonadotropin-releasing hormone, luteinizing hormone, progesterone receptor
2 Correspondence: Jon E. Levine, Department of Neurobiology and Physiology, Northwestern University, 2205 Tech Drive, Evanston, IL 60208. FAX: 847 467 2478
This article has been cited by other articles:
![]() |
A. Veiga-Lopez, O. I. Astapova, E. F. Aizenberg, J. S. Lee, and V. Padmanabhan Developmental Programming: Contribution of Prenatal Androgen and Estrogen to Estradiol Feedback Systems and Periovulatory Hormonal Dynamics in Sheep Biol Reprod, April 1, 2009; 80(4): 718 - 725. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. M. Jackson, K. M. Timmer, and D. L. Foster Sexual Differentiation of the External Genitalia and the Timing of Puberty in the Presence of an Antiandrogen in Sheep Endocrinology, August 1, 2008; 149(8): 4200 - 4208. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Demissie, M. Lazic, E. M. Foecking, F. Aird, A. Dunaif, and J. E. Levine Transient prenatal androgen exposure produces metabolic syndrome in adult female rats Am J Physiol Endocrinol Metab, August 1, 2008; 295(2): E262 - E268. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Huang, M. Acosta-Martinez, and J. E. Levine Ovarian Steroids Stimulate Adenosine Triphosphate-Sensitive Potassium (KATP) Channel Subunit Gene Expression and Confer Responsiveness of the Gonadotropin-Releasing Hormone Pulse Generator to KATP Channel Modulation Endocrinology, May 1, 2008; 149(5): 2423 - 2432. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. M. Garcia-Segura, B. Lorenz, and L. L DonCarlos The role of glia in the hypothalamus: implications for gonadal steroid feedback and reproductive neuroendocrine output Reproduction, April 1, 2008; 135(4): 419 - 429. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Manikkam, R. C. Thompson, C. Herkimer, K. B. Welch, J. Flak, F. J. Karsch, and V. Padmanabhan Developmental Programming: Impact of Prenatal Testosterone Excess on Pre- and Postnatal Gonadotropin Regulation in Sheep Biol Reprod, April 1, 2008; 78(4): 648 - 660. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Acosta-Martinez and J. E. Levine Regulation of KATP channel subunit gene expression by hyperglycemia in the mediobasal hypothalamus of female rats Am J Physiol Endocrinol Metab, June 1, 2007; 292(6): E1801 - E1807. [Abstract] [Full Text] [PDF] |
||||
![]() |
C A Wilson and D C Davies The control of sexual differentiation of the reproductive system and brain Reproduction, February 1, 2007; 133(2): 331 - 359. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Robinson Prenatal programming of the female reproductive neuroendocrine system by androgens. Reproduction, October 1, 2006; 132(4): 539 - 547. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.K. Blank, C.R. McCartney, and J.C. Marshall The origins and sequelae of abnormal neuroendocrine function in polycystic ovary syndrome Hum. Reprod. Update, July 1, 2006; 12(4): 351 - 361. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |