Central administration of Orphanin FQ inhibits GnRH secretion by ORL1 receptor in the median eminence of freely moving ovariectomized rats.
- Author:
Xiao-Fei AN
1
;
Ming HE
;
Yi FENG
;
Hao FENG
;
Jiang-Yi YU
Author Information
- Publication Type:Journal Article
- MeSH: Analysis of Variance; Animals; Dose-Response Relationship, Drug; Female; Gonadotropin-Releasing Hormone; metabolism; Median Eminence; metabolism; Narcotic Antagonists; Opioid Peptides; pharmacology; Ovariectomy; methods; Peptide Fragments; pharmacology; Radioimmunoassay; Rats; Rats, Sprague-Dawley; Receptors, Opioid; metabolism; Secretory Pathway; drug effects; Vasodilator Agents; pharmacology; Wakefulness; physiology
- From: Neuroscience Bulletin 2009;25(1):1-6
- CountryChina
- Language:English
-
Abstract:
OBJECTIVEThis study aimed to investigate the possible role of Orphanin FQ (OFQ) in the regulation of hypo-thalamic gonadotropin-releasing hormone (GnRH) secretion.
METHODSThe method of push-pull perfusion and radioimmuno-assay (RIA) were adopted to examine the secretory profile of GnRH in the median eminence (ME) in freely moving ovari-ectomized (OVX) rats after intracerebroventricular (icv) injection of OFQ and/or [Nphe(1)]NC(1-13)NH(2) (NC13), a competitive antagonists of the opioid receptor-like 1 receptor (ORL1 receptor).
RESULTSGnRH release from ME significantly decreased from 40 min to 80 min after the administration of 20 and 200 nmol OFQ in OVX rats (P < 0.05). This inhibitory effect of 20 nmol OFQ could be abolished by pretreatment with equal dose of NC13. More interestingly, GnRH secretion from ME was increased markedly 60 min after icv injection of 100 and 200 nmol NC13 (P < 0.05).
CONCLUSIONOur results suggested central administration of OFQ could inhibit the release of GnRH in the ME of hypothalamus through ORL1 receptor, providing further in vivo evidence supporting the role of OFQ in the control of GnRH secretion.
