Differential effects of intracerebroventricular glucagon-like peptide-1 on feeding and energy expenditure regulation.
Intracerebroventricular (i.c.v.) administration of glucagon-like peptide-1-(7-37) amide (GLP-1) has been shown to modulate food and water intake. The present studies further characterize the effects of i.c.v. GLP-1 in the regulation of energy balance in lean and obese animals. In both obese and lean Zucker rats, a single i.c.v. infusion of GLP-1 (1-30 microg) resulted in a dose-dependent reduction of food intake and decrease in respiratory quotient relative to the saline control during the first 2 h of the nocturnal cycle. In obese Zucker rats, the food intake was reduced by 73 +/- 11% of the control at the 30 microg dose, whereas a modest 45 +/- 18% reduction was observed in lean rats. Despite the large reduction in food intake seen with GLP-1, there was no compensatory decrease in nocturnal oxygen consumption in the obese Zucker rats. Interestingly, low doses of GLP-1 (1 microg) in lean Zucker rats, which had minimal effects on food intake, caused a 19 +/- 7% increase in O2 consumption during the first 2 h of the nocturnal cycle. These data suggest that central GLP-1 may be an important factor controlling negative energy balance in both the lean and obese Zucker rats.
Hwa
J J
JJ
Department of CNS and Cardiovascular Research, Schering-Plough Research Institute, Kenilworth, NJ 07033, USA. joyce.hwa@spcorp.com
Ghibaudi
L
L
Williams
P
P
Witten
M B
MB
Tedesco
R
R
Strader
C D
CD
D000704:Analysis of Variance; D000818:Animals; D004327:Drinking Behavior / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects*; D005934:Glucagon / Q000494:pharmacology*; D052216:Glucagon-Like Peptide 1; D007276:Injections, Intraventricular; D008297:Male; D009765:Obesity / Q000235:genetics*; D010446:Peptide Fragments / Q000494:pharmacology*; D011498:Protein Precursors / Q000494:pharmacology*; D051381:Rats; D011924:Rats, Zucker
D010446:Peptide Fragments; D011498:Protein Precursors; D052216:Glucagon-Like Peptide 1; D005934:Glucagon