Document Detail


Anorexia in rats caused by a valine-deficient diet is not ameliorated by systemic ghrelin treatment.
MedLine Citation:
PMID:  20006681     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Rodents exhibit aversive behavior toward a diet that lacks at least one of the essential amino acids. We sought to determine whether the particular form of anorexia caused by such diets could be ameliorated by the administration of orexigenic peptides while simultaneously analyzing the neural mechanisms underlying anorexia. Rats were fed a valine-deficient diet, which induced severe anorexia (reducing food consumption by 80%). The severe anorexia was associated with a significant decrease in the cerebrospinal fluid valine concentration and hyper-ghrelinemia. Between 6 and 12 days after initiation of the valine-deficient diet, we injected rats twice daily with valine and/or an orexigenic peptide (ghrelin, neuropeptide Y, or agouti-related protein) either i.p. or i.c.v.. We then measured dietary intake. An i.c.v. valine injection allowed earlier food intake compared with an i.p valine injection and increased the density of c-Fos-positive ependymal cells lining the third ventricle. Whereas an i.c.v. injection of ghrelin or neuropeptide Y increased consumption of the valine-deficient diet, i.p injection of ghrelin or i.c.v. injection of agouti-related protein did not. Following i.c.v. administration of either valine or ghrelin, we did not observe complete recovery of consumption of the valine-deficient diet. This may be due to the ineffectiveness of peripheral ghrelin and central agouti-related protein and/or to conditioned aversion to the valine-deficient diet. Since ghrelin is known to be involved in food anticipatory activities, whether the hyper-ghrelinemia observed in valine-deficient rats play role in foraging behavior other than food intake is the future study to be investigated.
Authors:
S Goto; K Nagao; M Bannai; M Takahashi; K Nakahara; K Kangawa; N Murakami
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-12-17
Journal Detail:
Title:  Neuroscience     Volume:  166     ISSN:  1873-7544     ISO Abbreviation:  Neuroscience     Publication Date:  2010 Mar 
Date Detail:
Created Date:  2010-02-01     Completed Date:  2010-05-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7605074     Medline TA:  Neuroscience     Country:  United States    
Other Details:
Languages:  eng     Pagination:  333-40     Citation Subset:  IM    
Copyright Information:
Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.
Affiliation:
Department of Veterinary Physiology, Miyazaki University, Miyazaki, Miyazaki 889-2192, Japan.
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MeSH Terms
Descriptor/Qualifier:
Agouti-Related Protein / metabolism,  pharmacology
Animals
Anorexia / drug therapy,  metabolism*,  physiopathology
Appetite / drug effects,  physiology*
Appetite Regulation / drug effects,  physiology*
Dietary Proteins / metabolism
Disease Models, Animal
Ependyma / cytology,  metabolism
Exploratory Behavior / drug effects,  physiology
Feeding Behavior / drug effects,  physiology
Food, Formulated
Ghrelin / metabolism*,  pharmacology
Hypothalamus / cytology,  drug effects,  metabolism
Male
Neuropeptide Y / metabolism,  pharmacology
Rats
Rats, Wistar
Third Ventricle / cytology,  metabolism
Valine / cerebrospinal fluid,  deficiency*,  pharmacology
Chemical
Reg. No./Substance:
0/Agouti-Related Protein; 0/Dietary Proteins; 0/Ghrelin; 0/Neuropeptide Y; 7004-03-7/Valine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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