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ID 25588
file
creator
Shiraishi, Jun-ichi
Yanagita, Kouichi
Fujita, Masanori
subject
β-Endorphin
food intake
insulin
central nervous system
neonatal chick
melanocortin system
NDC
Zoology
abstract
Pro-opiomelanocortin (POMC) neurons in the hypothalamus are direct targets of peripheral satiety signals, such as leptin and insulin in mammals. The stimulation of these signals activates hypothalamic POMC neurons and elevates POMC-derived melanocortin peptides that inhibit food intake in mammals. On the other hand, it has been recognized that β-endorphin, a post-translational processing of POMC, acts in an autoreceptor manner to the μ-opioid receptor (MOR) on POMC neurons, diminishing POMC neuronal activity in mammals. Recently, we found that central insulin functions as an anorexic peptide in chicks. Thus, the present study was done to elucidate whether β-endorphin affects the activation of POMC neurons by insulin in neonatal chicks. Consequently, quantitative real-time PCR analysis shows that intracerebroventricular (ICV) injection of insulin with β-endorphin significantly decreases brain POMC mRNA expression when compared with insulin alone. In addition, co-injection of MOR agonist (β-endorphin or [d-Ala2, N-MePhe4, Gly5-ol]-enkephalin (DAMGO)) significantly attenuates insulin-induced hypophagia in chicks. These data suggest that β-endorphin regulates the activity of the central melanocortin system, and its activation may provide an inhibitory feedback mechanism in the brain of neonatal chicks.
journal title
Neuroscience Letters
volume
Volume 439
issue
Issue 3
start page
227
end page
229
date of issued
2008-07
publisher
Elsevier Ireland Ltd
issn
0304-3940
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
Copyright (c) 2008 Elsevier Ireland Ltd
relation is version of URL
http://dx.doi.org/10.1016/j.neulet.2008.05.040
department
Graduate School of Biosphere Science