Opioids in the nucleus of the solitary tract are involved in
feeding in the rat.
Kotz, C. M., C. J. Billington, and A. S. Levine.
Departments of Food Science and Nutrition, Psychiatry and Medicine,
University of Minnesota, 1334 Eckles Avenue, St. Paul MN 55108, USA,
and Veterans Affairs Medical Center, One Veterans Drive, Research
Route 151, Minneapolis MN 55417, USA.
APStracts 3:0423R, 1996.
We evaluated the effect of selective opioid peptides and naltrexone on
feeding when injected into the nucleus of the solitary tract (NTS).
Zero, 1, 2, 4 and 8 nmol of [D-ala2-Me Phe4 enkephalin-Gly-ol5]
(DAMGO, mu agonist), dynorphin A (1-17) (DynA(1-17), kappa agonist),
and [D-ser-leu-enkephalin-tyr] (DSLET, delta agonist) were injected
into the NTS in satiated male rats and food intake was measured at 1,
2 and 4 h. Only DAMGO significantly increased feeding above control
levels at doses of 2, 4 and 8 nmol. Ten and 50 [mu]g naltrexone in
the NTS significantly decreased 18-h deprivation-induced feeding.
These data suggest that NTS opioid receptors (primarily mu) may be
involved in the regulation of feeding.
Received 4 March 1996; accepted in final form 25 October 1996.
APS Manuscript Number R133-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996