help button home button Endocrine Society Endocrinology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
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 Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jacobson, W.
Right arrow Articles by Kalra, S. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jacobson, W.
Right arrow Articles by Kalra, S. P.

Endocrinology, Vol 124, 199-206, Copyright © 1989 by Endocrine Society

ARTICLES

Decreases in mediobasal hypothalamic and preoptic area opioid ([3H]naloxone) binding are associated with the progesterone-induced luteinizing hormone surge

W Jacobson and SP Kalra
Department of Obstetrics and Gynecology, University of Florida College of Medicine, Gainesville 32610.

In view of evidence implicating hypothalamic opioid systems in the control of LH release, we have examined the binding of [3H]naloxone (NAL) to slices of mediobasal hypothalamus (MBH) and preoptic area (POA) during the induction of an afternoon LH surge (1630-1700 h) in estradiol benzoate (EB)-primed ovariectomized (OVX; day 0) rats by treatment with progesterone (P; day 2). Such a surge was invariably accompanied by a decrease from early morning (1000 h) values in the number of NAL-binding sites detectable in the MBH, while the affinity of the binding site was not affected over the course of the day. Time- course studies indicated that P injection at 1000 h on day 2 was followed by a transient midday elevation in the amount of NAL bound to slices of MBH; the binding decreased significantly before the onset of and during the LH surge. A similar diurnal change was not observed in MBH slices of either oil-treated OVX rats (controls) or EB-treated OVX rats, which displayed only a 2-fold increase in LH release in the afternoon. Further studies indicated a similar change in NAL binding to slices of the POA of EBP-treated rats. Since hypothalamic opioid systems inhibit LH release, the decrease in opioid binding to MBH as well as POA slices suggests that P may curtail the existing opioid inhibitory influence in these areas before and during the course of the afternoon LH surge.


This article has been cited by other articles:


Home page
 Endocr. Rev.Home page
A. E. Herbison
Multimodal Influence of Estrogen upon Gonadotropin-Releasing Hormone Neurons
Endocr. Rev., June 1, 1998; 19(3): 302 - 330.
[Abstract] [Full Text]

Home page
 J. Neurosci.Home page
C. B. Eckersell, P. Popper, and P. E Micevych
Estrogen-Induced Alteration of µ-Opioid Receptor Immunoreactivity in the Medial Preoptic Nucleus and Medial Amygdala
J. Neurosci., May 15, 1998; 18(10): 3967 - 3976.
[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
Copyright © 1989 by The Endocrine Society