|
|
||||||||
1 Department of Internal Medicine, Federal Armed Forces Hospital, D-89081 Ulm; and 2 Department of Internal Medicine II, Klinikum rechts der Isar, Technical University, D-81675 Munich, Germany
Glucagon-like peptide 1-(7-36) amide (GLP-1) potently inhibits rat feeding behavior after central administration. Because third ventricular injection of GLP-1 appeared to be less effective than lateral ventricular injection, we have reexamined this issue. In addition, we attempted to identify brain regions other than the paraventricular nucleus of the hypothalamus that are sensitive toward GLP-1-induced feeding suppression. Finally, we examined the local role of endogenous GLP-1 by specific GLP-1 receptor blockade. After lateral ventricular injection, GLP-1 significantly inhibited food intake of 24-h-fasted rats in a dose-dependent fashion with a minimal effective dose of 1 µg. After third ventricular injection, GLP-1 (1 µg) was similarly effective in suppressing food intake, which extends previous findings. Intracerebral microinjections of GLP-1 significantly suppressed food intake in the lateral (LH), dorsomedial (DMH), and ventromedial hypothalamus (VMH), but not in the medial nucleus of the amygdala. The minimal effective dose of GLP-1 was 0.3 µg at LH sites and 1 µg at DMH or VMH sites. LH microinjections of exendin-(9-39) amide, a GLP-1 receptor antagonist, at 1 or 2.5 µg did not alter feeding behavior in 24-h-fasted rats. In satiated animals, however, a single LH injection of 1 µg exendin-(9-39) amide significantly augmented food intake, but only during the first 20 min (0.6 vs. 0.1 g). With three repeated injections of 2.5 µg exendin-(9-39) amide every 20 min, 1-h food intake was significantly increased by 300%. These data strongly support and extend the concept of GLP-1 as a physiological regulator of food intake in the hypothalamus.
glucagon-like peptide 1; exendin-(9-39) amide; feeding behavior; rats; hypothalamus; lateral hypothalamus; ventromedial hypothalamus; dorsomedial hypothalamus; amygdala
This article has been cited by other articles:
![]() |
C. Wang, E. Bomberg, A. Levine, C. Billington, and C. M. Kotz Brain-derived neurotrophic factor in the ventromedial nucleus of the hypothalamus reduces energy intake Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R1037 - R1045. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Persson A look back at a successful year Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2005; 289(6): R1535 - R1535. [Full Text] [PDF] |
||||
![]() |
W. A. Cupples Physiological regulation of food intake Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2005; 288(6): R1438 - R1443. [Full Text] [PDF] |
||||
![]() |
P. K. Chelikani, A. C. Haver, and R. D. Reidelberger Intravenous infusion of glucagon-like peptide-1 potently inhibits food intake, sham feeding, and gastric emptying in rats Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2005; 288(6): R1695 - R1706. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. A. Cupples Endo-neuro-endocrine incretin pathways Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2004; 286(2): R250 - R250. [Full Text] [PDF] |
||||
![]() |
W. A. Cupples Peptides that regulate food intake Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2003; 284(6): R1370 - R1374. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |