Spontaneous meal is associated with distinct changes in the
endogenous levels of bombesin-like peptides and corticotropin
-releasing factor in specific brain nuclei.
Plamondon, Hlne, and Zul Merali.
School of Psychology and Dept. of Pharmacology, 11 Marie Curie (Rm
204 VNR), University of Ottawa, Ottawa, Ontario, Canada. K1N 9A9
APStracts 3:0254R, 1996.
Bombesin (BN) and corticotropin-releasing factor (CRF) have both been
shown to induce satiety in rats, when injected centrally. The present
study assessed temporal changes in the utilization of BN- and CRF
-like peptides in relationship to feeding status; fluctuations that
may indicate the physiological participation of these peptides in the
regulation of feeding. Alterations in the endogenous levels of CRF
and BN-like peptides associated with the initial spontaneous meal of
the nocturnal cycle were determined in fifteen hypothalamic and
extrahypothalamic brain nuclei, in the following three groups of
rats: 1) a preprandial group consisting of rats sacrificed before
feeding, 2) a prandial group consisting of rats sacrificed during the
meal and, 3) a postprandial group consisting of rats sacrificed 8-12
min following the meal. Findings revealed site-specific changes in BN
and CRF content during the course of a meal. During ingestion, levels
of BN were significantly elevated at the paraventricular, arcuate and
dorsomedial nuclei of the hypothalamus, and reduced at the nucleus
accumbens. In the case of CRF, feeding-related alterations were
observed at the lateral (LH) and ventromedial (VMH) hypothalamic
nuclei and at the central nucleus of the amygdala (Ce). At the LH,
CRF content dropped following feeding as compared to preprandial
levels. At the VMH, CRF levels were significantly elevated both
before and after food intake when compared to prandial levels. In
contrast, at the Ce marked increases in CRF concentrations were
observed during ingestion. These data demonstrate for the first time,
site-specific fluctuations of BN and CRF in relationship to the
animalaes feeding status, and suggest that these peptides may play a
role in the regulation of food intake.
Received 19 January 1996; accepted in final form 14 June 1996.
APS Manuscript Number R30-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96