The potency of naloxone's anorectic effect on high carbohydrate and
high fat diets is dependent on diet preference in npy--and
deprivation-induced feeding.
Glass, Michael J., Martha Grace, James P. Cleary, Charles J.
Billington, and Allen S. Levine.
Veterans Affairs Medical Center, One Veterans Drive, Research
Service (151),Minneapolis, Minnesota 55417, Departments of
Psychiatry, Food Science and Nutrition, Medicine, Psychology,
Minneapolis, Minnesota 55455
APStracts 3:0127R, 1996.
Modulation of feeding behavior by NPY and opioids is well established,
but the possibility that these neural influences provoke specific
appetites, NPY for carbohydrate and opioids for fat, has also been
considered. In other studies intake of standard chow after NPY
stimulation can be blocked by naloxone, indicating an interaction
between these systems in the regulation of feeding. The present
experiments examined the nature of NPY-opioid interactions in diet
selection. Rats were administered NPY and naloxone concurrently, then
chose between high fat and high carbohydrate diets. Subcutaneous
administration of naloxone (0.01-0.3 mg/kg) potently reduced intake
of the preferred diet, but not the non-preferred diet. A similar
pattern of selection was seen in a separate experiment where the same
doses of naloxone were administered after 24-hr food deprivation.
These data supports the idea that the opioid system mediates the
"rewarding" aspects of feeding.
Received 25 October 1995; accepted in final form 18 January 1996.
APS Manuscript Number R664-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 16 April 96