| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
ARTICLES |
Department of Obstetrics and Gynaecology, University of British Columbia, Vancouver, Canada V6H 3V5
Address all correspondence and requests for reprints to: Dr. Peter C. K. Leung, Department of Obstetrics and Gynaecology, University of British Columbia, Room 2H304490 Oak Street, Vancouver, British Columbia, Canada V6H 3V5. E-mail: peleung{at}interchange.ubc.ca
There is evidence that GnRH and its binding sites are expressed in numerous extrapituitary tissues, including the primate ovary. However, the factors that regulate ovarian GnRH and its receptor (GnRH-R) remain poorly characterized. Since gonadal steroids are key regulators of ovarian functions, the present study investigated the role of 17ß-estradiol (E2) in regulating GnRH and GnRH-R messenger RNA (mRNA) from human granulosa-luteal cells (hGLCs). RT-PCR was used to isolate the ovarian GnRH-R transcript equivalent to the full-length coding region in the pituitary from hGLCs. Sequence analysis revealed that the ovarian GnRH-R mRNA is identical to its pituitary counterpart. Basal expression studies indicated that GnRH and GnRH-R mRNA levels significantly increased with time in vitro, reaching levels of 160% and 170% on day 8 and 10 of culture, respectively (P < 0.05). Treatment with various concentrations of estradiol (1100 nM) for 24 h resulted in a dose-dependent decrease (P < 0.05) in GnRH and GnRH-R mRNA levels. Time course studies indicated that short-term treatment (6 h) with E2 (1 nM) had no significant effect on GnRH mRNA levels, while long-term treatment (48 h) with E2 resulted in a 40% decrease (P < 0.001) in GnRH mRNA levels. In contrast, GnRH-R mRNA levels exhibited a biphasic pattern, such that a short-term treatment (6 h) with E2 increased GnRH-R mRNA levels by 20% (P < 0.05), whereas long-term treatment (48 h) resulted in a 60% decrease (P < 0.001) in GnRH-R expression in hGLCs. Cotreatment of estradiol and tamoxifen blocked the E2 induced-regulation of GnRH and its receptor mRNAs, indicating that the E2 effect was mediated through its receptor. In summary, our studies demonstrate that the ovary possesses an intrinsic GnRH axis that is regulated during luteinization in vitro, and that E2 is capable of regulating GnRH and its receptor in the human ovary.
This article has been cited by other articles:
![]() |
B. A.T. Rodriguez, A. S.L. Cheng, P. S. Yan, D. Potter, F. J. Agosto-Perez, C. L. Shapiro, and T. H.-M. Huang Epigenetic repression of the estrogen-regulated Homeobox B13 gene in breast cancer Carcinogenesis, July 1, 2008; 29(7): 1459 - 1465. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Prange-Kiel, H. Jarry, M. Schoen, P. Kohlmann, C. Lohse, L. Zhou, and G. M. Rune Gonadotropin-releasing hormone regulates spine density via its regulatory role in hippocampal estrogen synthesis J. Cell Biol., January 28, 2008; 180(2): 417 - 426. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Metallinou, B. Asimakopoulos, A. Schroer, and N. Nikolettos Gonadotropin-Releasing Hormone in the Ovary Reproductive Sciences, December 1, 2007; 14(8): 737 - 749. [Abstract] [PDF] |
||||
![]() |
S Darby, J Stockley, M M Khan, C N Robson, H Y Leung, and V J Gnanapragasam Expression of GnRH type II is regulated by the androgen receptor in prostate cancer Endocr. Relat. Cancer, September 1, 2007; 14(3): 613 - 624. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. K. Cheng and P. C. K. Leung Molecular Biology of Gonadotropin-Releasing Hormone (GnRH)-I, GnRH-II, and Their Receptors in Humans Endocr. Rev., April 1, 2005; 26(2): 283 - 306. [Abstract] [Full Text] [PDF] |
||||
![]() |
B.-S. An, J.-H. Choi, K.-C. Choi, and P. C. K. Leung Differential Role of Progesterone Receptor Isoforms in the Transcriptional Regulation of Human Gonadotropin-Releasing Hormone I (GnRH I) Receptor, GnRH I, and GnRH II J. Clin. Endocrinol. Metab., February 1, 2005; 90(2): 1106 - 1113. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Maudsley, L. Davidson, A. J. Pawson, R. Chan, R. L. de Maturana, and R. P. Millar Gonadotropin-Releasing Hormone (GnRH) Antagonists Promote Proapoptotic Signaling in Peripheral Reproductive Tumor Cells by Activating a G{alpha}i-Coupling State of the Type I GnRH Receptor Cancer Res., October 15, 2004; 64(20): 7533 - 7544. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Young and R. L. Stouffer Gonadotropin and Steroid Regulation of Matrix Metalloproteinases and Their Endogenous Tissue Inhibitors in the Developed Corpus Luteum of the Rhesus Monkey During the Menstrual Cycle Biol Reprod, January 1, 2004; 70(1): 244 - 252. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. K. Cheng, B. K. C. Chow, and P. C. K. Leung An Activator Protein 1-Like Motif Mediates 17{beta}-Estradiol Repression of Gonadotropin-Releasing Hormone Receptor Promoter via an Estrogen Receptor {alpha}-Dependent Mechanism in Ovarian and Breast Cancer Cells Mol. Endocrinol., December 1, 2003; 17(12): 2613 - 2629. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. M. Siler-Khodr, M. Grayson, and C. A. Eddy Action of Gonadotropin-Releasing Hormone II on the Baboon Ovary Biol Reprod, April 1, 2003; 68(4): 1150 - 1156. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Khosravi and P. C. K. Leung Differential Regulation of Gonadotropin-Releasing Hormone (GnRH)I and GnRHII Messenger Ribonucleic Acid by Gonadal Steroids in Human Granulosa Luteal Cells J. Clin. Endocrinol. Metab., February 1, 2003; 88(2): 663 - 672. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. K. Cheng, C. M. Yeung, B. K. C. Chow, and P. C. K. Leung Characterization of a New Upstream GnRH Receptor Promoter in Human Ovarian Granulosa-Luteal Cells Mol. Endocrinol., July 1, 2002; 16(7): 1552 - 1564. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. H. Kim, A. Wolfe, G. R. Smith, S. A. Tobet, and S. Radovick Promoter Sequences Targeting Tissue-specific Gene Expression of Hypothalamic and Ovarian Gonadotropin-releasing Hormone in Vivo J. Biol. Chem., February 8, 2002; 277(7): 5194 - 5202. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. M. M. Woo, C.-J. Tai, S. K. Kang, P. S. Nathwani, S. F. Pang, and P. C. K. Leung Direct Action of Melatonin in Human Granulosa-Luteal Cells J. Clin. Endocrinol. Metab., October 1, 2001; 86(10): 4789 - 4797. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. F. Palter, A. B. Tavares, A. Hourvitz, J. D. Veldhuis, and E. Y. Adashi Are Estrogens of Import to Primate/Human Ovarian Folliculogenesis? Endocr. Rev., June 1, 2001; 22(3): 389 - 424. [Abstract] [Full Text] [PDF] |
||||
![]() |
O. Ortmann, J.M. Weiss, and K. Diedrich Embryo implantation and GnRH antagonists: Ovarian actions of GnRH antagonists Hum. Reprod., April 1, 2001; 16(4): 608 - 611. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. K. Kang, C.-J. Tai, P. S. Nathwani, and P. C. K. Leung Differential Regulation of Two Forms of Gonadotropin-Releasing Hormone Messenger Ribonucleic Acid in Human Granulosa-Luteal Cells Endocrinology, January 1, 2001; 142(1): 182 - 192. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |