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


     

BOR - Papers in Press, published online ahead of print August 20, 2003.
Biol Reprod 2003, 10.1095/biolreprod.103.016956
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
69/6/2015    most recent
biolreprod.103.016956v1
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 Scott, C. J.
Right arrow Articles by Tilbrook, A. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Scott, C. J.
Right arrow Articles by Tilbrook, A. J.
Agricola
Right arrow Articles by Scott, C. J.
Right arrow Articles by Tilbrook, A. J.
BIOLOGY OF REPRODUCTION 69, 2015–2021 (2003)
DOI: 10.1095/biolreprod.103.016956
© 2003 by the Society for the Study of Reproduction, Inc.

Neuroendocrinology

Effect of Testosterone and Season on Proenkephalin Messenger RNA Expression in the Preoptic Area of the Hypothalamus in the Ram1

Christopher J. Scott2,3,4, Michael Mariani4, Iain J. Clarke5, and Alan J. Tilbrook4

Department of Physiology,4 Monash University, Victoria, Australia Prince Henry's Institute of Medical Research,5 Clayton, Victoria, Australia

Enkephalin appears to exert an inhibitory action on LH secretion, but whether testosterone regulates enkephalin gene expression is unknown. This study tested the hypothesis that testosterone and/or season modulate preproenkephalin mRNA expression in specific areas of the hypothalamus. Romney Marsh rams were castrated (wethers) either during the breeding season or nonbreeding season and received intramuscular injections of either oil or testosterone propionate (five/group). Blood samples were taken for the assay of plasma LH and testosterone. Preproenkephalin mRNA expression was quantified in hypothalamic sections by in situ hybridization. Mean plasma LH concentrations were reduced and the interpulse interval for LH pulses was greater in testosterone propionate-treated wethers compared with oil-treated wethers, with no change in LH pulse amplitude. Testosterone propionate treatment reduced proenkephalin expression in the diagonal band of Broca, the caudal preoptic area, and the bed nucleus of the stria terminalis. Seasonal differences in proenkephalin expression were observed in the bed nucleus of the stria terminalis, lateral septum, periventricular nucleus, and paraventricular nucleus. No differences were observed between treatments in seven other regions examined. We conclude that testosterone and season regulate proenkephalin mRNA levels in the preoptic area/hypothalamus in the ram in a region-specific manner.

1 Supported by grants to C.J.S. and A.J.T. from the National Health and Medical Research Council of Australia and Monash University.

2 Correspondence: Chris Scott, School of Biomedical Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga, New South Wales 2678, Australia. FAX: 61 2 69332587; chscott{at}csu.edu.au

3 Current address: School of Biomedical Science, Charles Sturt University, Wagga Wagga, New South Wales, Australia






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2003 by the Society for the Study of Reproduction.