Document Detail

Effects of anorectic drugs on food intake under progressive-ratio and free-access conditions in rats.
MedLine Citation:
PMID:  15693523     Owner:  NLM     Status:  MEDLINE    
The effects of two anorectic drugs, dexfenfluramine and phentermine, on food intake under different food-access conditions were examined. Experiment 1 compared the effects of these drugs on food intake under a progressive-ratio (PR) schedule and free-access conditions. Dexfenfluramine decreased food intake under both conditions, but the doses required to decrease intake under free-access conditions were higher than those required to reduce intake under the PR condition. Intermediate doses of phentermine sometimes increased breaking points, and higher doses decreased them. Phentermine decreased food intake at the same doses under both access conditions. Thus the potency of dexfenfluramine, but not phentermine, to decrease food-maintained behavior depended upon the food-access condition. Experiment 2 used a novel mixed progressive-ratio schedule of food delivery to study the duration of drug effects. Sessions consisted of five components separated by 3-hr timeouts. The ratio requirement reset at the beginning of each component and a new breaking point was obtained. Both dexfenfluramine and phentermine dose-dependently decreased breaking points early in the session. In some rats, compensatory increases in breaking point were observed. That is, breaking points later in the session increased over control levels, resulting in no change in the total number of food pellets earned for the session compared to control. The present findings suggest that the effects of some anorectic drugs depend upon the access conditions for food; increasing the effort to obtain food may enhance their ability to decrease food-maintained behavior.
Mark G LeSage; David Stafford; John R Glowa
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of the experimental analysis of behavior     Volume:  82     ISSN:  0022-5002     ISO Abbreviation:  J Exp Anal Behav     Publication Date:  2004 Nov 
Date Detail:
Created Date:  2005-02-07     Completed Date:  2005-05-10     Revised Date:  2009-11-18    
Medline Journal Info:
Nlm Unique ID:  0203727     Medline TA:  J Exp Anal Behav     Country:  United States    
Other Details:
Languages:  eng     Pagination:  275-92     Citation Subset:  IM    
Louisiana State University Health Sciences Center in Shreveport, USA.
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MeSH Terms
Appetite Depressants / administration & dosage,  adverse effects*,  pharmacology
Behavior, Animal / drug effects
Conditioning (Psychology) / drug effects*
Dexfenfluramine / administration & dosage,  adverse effects*,  pharmacology
Dose-Response Relationship, Drug
Energy Intake / drug effects*
Phentermine / administration & dosage,  adverse effects*,  pharmacology
Grant Support
Reg. No./Substance:
0/Appetite Depressants; 122-09-8/Phentermine; 3239-44-9/Dexfenfluramine

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

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