Hypothalamic ghrelin treatment modulates NPY-but not CRH-ergic activity in adrenalectomized rats subjected to food restriction: Evidence of a novel hypothalamic ghrelin effect

Details

Ressource 1Download: serval:BIB_4F35381F77E9.P001 (271.21 [Ko])
State: Public
Version: author
License: Not specified
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.
Serval ID
serval:BIB_4F35381F77E9
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Hypothalamic ghrelin treatment modulates NPY-but not CRH-ergic activity in adrenalectomized rats subjected to food restriction: Evidence of a novel hypothalamic ghrelin effect
Journal
Endocrine
Author(s)
Spinedi  E., Voirol  M. J., Verdumo  C., Giacominni  M., Pralong  F., Gaillard  R. C.
ISSN
0969-711X (Print)
Publication state
Published
Issued date
06/2006
Volume
29
Number
3
Pages
477-84
Notes
Evaluation Studies
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jun
Abstract
It has been proposed that ghrelin induces food intake by a mechanism due to the stimulation of hypothalamic NPY-ergic activity. It is recognized that bilateral adrenalectomy (ADX) enhances hypothalamic CRH-ergic function and reduces appetite. Thus, the aim of the present study was to test whether, icv-administered, ghrelin modulates NPY- and CRH-ergic functions after food restriction (FR) and glucocorticoid deprivation. For this purpose, 1 microg ghrelin was administered icv to ad libitum (AL) eating and to corticosterone (B)-depleted (ADX) and -replete (sham and ADX+B) male animals habituated, for 15 d, to FR. Food intake, hypothalamic function, and peripheral ghrelin, ACTH, and B concentrations were evaluated 2 h after ghrelin administration. Results indicate that while icv ghrelin treatment stimulated 2-h food intake in AL rats, it failed to do so in sham- and ADX+B-FR animals; moreover, 2-h food intake was inhibited by icv ghrelin treatment in ADX-FR rats. Regarding peripheral hormone levels: (a) basal circulating ghrelin levels, already enhanced (vs AL rats) by FR, significantly increased 2 h after icv ghrelin treatment in AL and sham-FR rats; (b) central ghrelin treatment stimulated ACTH secretion in circulation of AL and glucocorticoid-replete-FR rats; and (c) B circulating levels remained unchanged after ghrelin treatment, although they were in relation to the food intake condition of rats. Finally, hypothalamic NPY mRNA expression was enhanced by FR and, in response to icv ghrelin treatment, it decreased in ADX-FR rats only. ADX-enhanced hypothalamic CRH mRNA levels were reduced by ghrelin icv administration only when animals received B replacement therapy. Our data indicate an inhibitory effect of hypothalamic ghrelin on NPY-ergic activity in FR rats lacking endogenous glucocorticoid.
Keywords
Adrenalectomy Adrenocorticotropic Hormone/blood Animals Body Weight Corticotropin-Releasing Hormone/*metabolism Drug Administration Routes Eating/drug effects Food Deprivation/*physiology Gene Expression/drug effects Glucocorticoids/physiology Hypothalamus/*drug effects/metabolism Injections/methods Leptin/blood Male Neuropeptide Y/*metabolism Peptide Hormones/administration & dosage/blood/*pharmacology RNA, Messenger/metabolism Rats Rats, Wistar
Pubmed
Web of science
Open Access
Yes
Create date
25/01/2008 16:26
Last modification date
01/10/2019 6:17
Usage data