Central infusions of leptin and GLP-1-(7-36) amide differentially stimulate c-FLI in the rat brain.
Recently, glucagon-like peptide-1-(7-36) amide (GLP-1) and leptin have been implicated in the regulation of food intake. In the present study, we compared the effects of third ventricular administration (i3vt) of leptin (3.5 micrograms) and GLP-1 (10.0 micrograms) on short-term food intake and c-Fos-like immunoreactivity (c-FLI) in hypothalamic, limbic, and hindbrain areas in the rat. Relative to controls, infusion of leptin or GLP-1 (3 h before lights off) significantly reduced food intake over the first 2 h in the dark phase (53 and 63%, respectively). In different rats, infusion of leptin or GLP-1 elevated c-FLI in the paraventricular hypothalamus and central amygdala. Furthermore, leptin selectively elevated c-FLI in the dorsomedial hypothalamus, whereas GLP-1 selectively elevated c-FLI in the nucleus of the solitary tract, area postrema, lateral parabrachial nucleus, and arcuate hypothalamic nucleus. The fact that most of the c-FLI after leptin or GLP-1 administration was observed in separate regions within the central nervous system (CNS) suggests different roles for leptin and GLP-1 in the CNS regulation of food intake and body weight.
Department of Psychology, University of Washington, Seattle 98195-1525, USA. gvandijk@u.washington.edu
G
G
Van Dijk
T E
TE
Thiele
J C
JC
Donahey
L A
LA
Campfield
F J
FJ
Smith
P
P
Burn
I L
IL
Bernstein
S C
SC
Woods
R J
RJ
Seeley
D000818:Animals; D001921:Brain / Q000378:metabolism / Q000502:physiology*; D004435:Eating / Q000187:drug effects; D005934:Glucagon; D052216:Glucagon-Like Peptide 1; D004763:Glucagon-Like Peptides; D007150:Immunohistochemistry; D007276:Injections, Intraventricular; D020738:Leptin; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D011506:Proteins / Q000494:pharmacology*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
D020738:Leptin; D010446:Peptide Fragments; D011506:Proteins; D016760:Proto-Oncogene Proteins c-fos; C055453:glucagon-like peptide 1 (7-36)amide; D004763:Glucagon-Like Peptides; D052216:Glucagon-Like Peptide 1; D005934:Glucagon