Skip Navigation



Hum. Reprod. Advance Access published online on July 2, 2009
Human Reproduction, doi:10.1093/humrep/dep237
This Article
Right arrow Full Text
Right arrow Full Text (PDF )
Right arrow All Versions of this Article:
24/10/2618    most recent
dep237v1
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Gordon, A.
Right arrow Articles by Sánchez-Criado, J. E.
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gordon, A.
Right arrow Articles by Sánchez-Criado, J. E.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2009. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Activation of estrogen receptor-{alpha} induces gonadotroph progesterone receptor expression and action differently in young and middle-aged ovariectomized rats

Ana Gordon1,3, Rafaela Aguilar1, José C. Garrido-Gracia1, Silvia Guil-Luna2, Raquel Sánchez-Cespedes2, Yolanda Millán2, Juana Martín de las Mulas2 and José E. Sánchez-Criado1

1 Departments of Cell Biology, Physiology and Immunology, University of Córdoba, Córdoba, Spain 2 Departments of Comparative Pathology, University of Córdoba, Córdoba, Spain

3 Correspondence address. Section of Physiology, Faculty of Medicine, Avda. Menendez Pidal s/n, 14004 Córdoba, Spain. Tel: +34-957-218283; E-mail: anagordonbc{at}gmail.com

BACKGROUND: We attempted to define the effect of estrogen receptor (ER){alpha} activation on gonadotroph progesterone receptor (PR) expression (mRNA and protein) and action (GnRH-stimulated and GnRH self-priming) in short- and long-term ovariectomized (OVX) rats.

METHODS: Two weeks or 1 year after OVX, rats were injected over 3 days with 125 µg/kg of estradiol benzoate (EB), 7.5 mg/kg of the selective ER{alpha} agonist propylpyrazole triol (PPT), or 15 mg/kg of the selective ER modulator tamoxifen (TX). Controls were given 0.2 ml oil. The last day of ER analog treatment, half of the rats in each group received 25 mg/kg of progesterone (P). The next day, anterior pituitaries were removed and analyzed for PR-AB mRNA and protein. Gonadotrophin secretion in incubated pituitaries was also measured.

RESULTS: (i) PR mRNA expression was higher in young than in middle-aged OVX rats although PR protein was absent in pituitaries from both groups of OVX rats; (ii) activation of ER{alpha} reduced gonadotroph hypertrophy and increased PR mRNA and protein expression (EB > PPT > TX) more efficiently in young than in middle-aged rats, (iii) ER agonists elicited GnRH-stimulated LH and FSH secretion in young but only FSH secretion in middle-aged OVX rats, (iv) evaluated by peak LH concentrations, GnRH self-priming was observed in both groups of OVX rats and (v) P down-regulated PR protein expression in young, and to a lesser extent, in middle-aged OVX rats, in close association with PR-dependent GnRH self-priming.

CONCLUSIONS: Middle-aged OVX rats exhibited clear-cut LH, but not FSH, secretory defects in pituitary sensitivity to estrogen and P.

Key words: progesterone receptor expression/gonadotrophin secretion/GnRH self-priming/tamoxifen/estrogen receptor-{alpha} agonists

Submitted on February 12, 2009; resubmitted on April 29, 2009; accepted on June 9, 2009.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.