Biol Reprod 2009 SSR Annual Meeting Abstracts
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
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 My Folders
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 Luza, S. M.
Right arrow Articles by Lara, H. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Luza, S. M.
Right arrow Articles by Lara, H. E.
Agricola
Right arrow Articles by Luza, S. M.
Right arrow Articles by Lara, H. E.

Biology of Reproduction, Vol 52, 398-404, Copyright © 1995 by Society for the Study of Reproduction

ARTICLES

Hypothalamic changes in norepinephrine release in rats with estradiol valerate-induced polycystic ovaries

SM Luza, L Lizama, RA Burgos and HE Lara
Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago.

Chronic anovulation and polycystic ovaries (PCO) can be induced by a single i.m. injection of estradiol valerate (EV, 2 mg in oil) in the rat. Constant exposure to high plasma levels of estradiol provokes a neurotoxic effect on the hypothalamic neurons, including those from the arcuate nucleus. Because of the important participation of hypothalamic norepinephrine (NE) in the regulation of GnRH release and the possible noxious effect of prolonged exposure of these neurons to estradiol, our interest was to study the activity of the noradrenergic neurons innervating the hypothalamus. We analyzed the biosynthesis, content, and release of NE from the noradrenergic nerve terminals of the hypothalamus during the PCO condition. We found a decrease in tyrosine hydroxylase (TH) activity and in the content of dopamine (DA) in the anterior hypothalamus after 2 mo of EV injection, whereas dopamine-beta- hydroxylase (D beta H) was increased without changes in NE content. No variations in TH activity or in DA and NE contents in the medial hypothalamus were observed, but a decrease in D beta H activity was evident. After 2 mo of EV administration, an increase in the electrically induced release of NE from anterior hypothalamic blocks incubated in vitro was detected; this effect was not evidenced in the medial hypothalamus. After 5 mo of EV administration, release of NE increased in anterior hypothalamic blocks but decreased in medial hypothalamic tissue. The inhibitory effect of morphine on NE release found in control animals was increased in the hypothalamus from PCO rats, suggesting an increased number of mu-opioid binding sites in noradrenergic neurons.(ABSTRACT TRUNCATED AT 250 WORDS)




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1995 by the Society for the Study of Reproduction.