Biol Reprod
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

BOR - Papers in Press, published online ahead of print October 5, 2005.
Biol Reprod 2005, 10.1095/biolreprod.105.044685
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
74/1/202    most recent
biolreprod.105.044685v2
biolreprod.105.044685v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
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 Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Arreguin-Arevalo, J. A.
Right arrow Articles by Nett, Terry. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Arreguin-Arevalo, J. A.
Right arrow Articles by Nett, Terry. M.
Agricola
Right arrow Articles by Arreguin-Arevalo, J. A.
Right arrow Articles by Nett, Terry. M.
BIOLOGY OF REPRODUCTION 74, 202–208 (2006)
DOI: 10.1095/biolreprod.105.044685
© 2006 by the Society for the Study of Reproduction, Inc.

Research Article

A Nongenomic Action of Estradiol as the Mechanism Underlying the Acute Suppression of Secretion of Luteinizing Hormone in Ovariectomized Ewes1

J. Alejandro Arreguin-Arevalo, and Terry. M. Nett 2

Department of Biomedical Science, Colorado State University, Fort Collins, Colorado 80523

ABSTRACT

The objective of the present study was to determine how rapidly estradiol (E2) was able to suppress the secretion of LH in ovariectomized (OVX) ewes and to evaluate the ability of conjugated forms of E2 (E2 conjugated to BSA [1,3,5(10)-estratrien-3,17ß-diol-6-one-6-carboxymethyloxime:BSA [E2-BSA] and a novel conjugate, E2 conjugated to a small peptide [E2-PEP]) to mimic the actions of E2 on secretion of LH and FSH. Animals (n = 5–6 per group) were given infusions for 4 h of 50 µg of E2 or equimolar concentrations of E2-BSA or E2-PEP. Treatments with E2, E2-BSA, and E2-PEP each induced an acute suppression of LH secretion (<20 min, P < 0.01). In contrast, E2, but not E2-BSA or E2-PEP, induced the characteristic preovulatory-like surge of LH (at 10 h after priming treatment) and decreased secretion of FSH (at 4 h after priming treatment). In conclusion, the acute inhibition of LH secretion induced by E2 in OVX ewes supports the concept of a nongenomic action as the mechanism underlying the sudden suppression in secretion of LH. In addition, the fact that conjugated forms of E2 mimicked only the acute suppression of secretion of LH, without inducing the putative genomic actions on secretion of LH or FSH (i.e., a preovulatory-like surge), suggests that the acute effect of E2 may be mediated via the plasma membrane.

estradiol, estradiol receptor, follicle-stimulating hormone, luteinizing hormone, pituitary

FOOTNOTES

1 Supported by the National Research Initiative, competitive grant no. 2005-35203-15376, from the USDA Cooperative State Research, Education, and Extension Service, and by a grant from the Colorado State University Agricultural Experiments Station. The academic program of J.A.A.-A. was supported by the National Council for Science and Technology (CONACYT-Mexico) and the National Institute for Research in Forestry, Agriculture and Livestock (INIFAP-Mexico).

2 Correspondence: Terry M. Nett, Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Science, 3801 W. Rampart Rd., Fort Collins, CO 80523-1683. FAX: 970 491 3557; terry.nett{at}colostate.edu






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2006 by the Society for the Study of Reproduction.