scholarly journals Hindbrain leptin and glucagon-like-peptide-1 receptor signaling interact to suppress food intake in an additive manner

2012 ◽  
Vol 36 (12) ◽  
pp. 1522-1528 ◽  
Author(s):  
S Zhao ◽  
S E Kanoski ◽  
J Yan ◽  
H J Grill ◽  
M R Hayes
Keyword(s):  
Food Intake ◽  
Receptor Signaling ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

scholarly journals The food intake-suppressive effects of glucagon-like peptide-1 receptor signaling in the ventral tegmental area are mediated by AMPA/kainate receptors

2013 ◽  
Vol 305 (11) ◽  
pp. E1367-E1374 ◽  
Author(s):  
Elizabeth G. Mietlicki-Baase ◽  
Pavel I. Ortinski ◽  
Laura E. Rupprecht ◽  
Diana R. Olivos ◽  
Amber L. Alhadeff ◽  
...  
Keyword(s):  
Food Intake ◽  
Ventral Tegmental Area ◽  
Dopamine Neurons ◽  
Kainate Receptors ◽  
System Control ◽  
Receptor Signaling ◽  
Palatable Food ◽  
Glucagon Like Peptide ◽  
Ventral Tegmental ◽  
Glucagon Like Peptide 1

Glucagon-like peptide-1 receptor (GLP-1R) activation in the ventral tegmental area (VTA) is physiologically relevant for the control of palatable food intake. Here, we tested whether the food intake-suppressive effects of VTA GLP-1R activation are mediated by glutamatergic signaling within the VTA. Intra-VTA injections of the GLP-1R agonist exendin-4 (Ex-4) reduced palatable high-fat food intake in rats primarily by reducing meal size; these effects were mediated in part via glutamatergic AMPA/kainate but not NMDA receptor signaling. Additional behavioral data indicated that GLP-1R expressed specifically within the VTA can partially mediate the intake- and body weight-suppressive effects of systemically administered Ex-4, offering the intriguing possibility that this receptor population may be clinically relevant for food intake control. Intra-VTA Ex-4 rapidly increased tyrosine hydroxylase levels within the VTA, suggesting that GLP-1R activation modulates VTA dopaminergic signaling. Further evidence for this hypothesis was provided by electrophysiological data showing that Ex-4 increased the frequency of AMPA-mediated currents and reduced the paired/pulse ratio in VTA dopamine neurons. Together, these data provide novel mechanisms by which GLP-1R agonists in the mesolimbic reward system control for palatable food intake.

scholarly journals Endogenous Glucagon-like Peptide-1 Receptor Signaling in the Nucleus Tractus Solitarius is Required for Food Intake Control

2016 ◽  
Vol 42 (7) ◽  
pp. 1471-1479 ◽  
Author(s):  
Amber L Alhadeff ◽  
Blake D Mergler ◽  
Derek J Zimmer ◽  
Christopher A Turner ◽  
David J Reiner ◽  
...  
Keyword(s):  
Food Intake ◽  
Nucleus Tractus Solitarius ◽  
Receptor Signaling ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Intake Control

scholarly journals GLP-1 receptor signaling contributes to anorexigenic effect of centrally administered oxytocin in rats

2002 ◽  
Vol 283 (1) ◽  
pp. R99-R106 ◽  
Author(s):  
Linda Rinaman ◽  
Elizabeth E. Rothe
Keyword(s):  
Food Intake ◽  
Receptor Antagonist ◽  
Male Rats ◽  
Neural Systems ◽  
Neural Pathways ◽  
Receptor Signaling ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Access To Food ◽  
Anorexigenic Effect

The present study examined possible interactions between central glucagon-like peptide-1 (GLP-1) and oxytocin (OT) neural systems by determining whether blockade of GLP-1 receptors attenuates OT-induced anorexia and vice versa. Male rats were acclimated to daily 4-h food access. In the first experiment, rats were infused centrally with GLP-1 receptor antagonist or vehicle, followed by an anorexigenic dose of synthetic OT. Access to food began 20 min later. Cumulative food intake was measured every 30 min for 4 h. In the second experiment, rats were infused with OT receptor blocker or vehicle, followed by synthetic GLP-1 [(7–36) amide]. Subsequent food intake was monitored as before. The anorexigenic effect of OT was eliminated in rats pretreated with the GLP-1 receptor antagonist. Conversely, GLP-1-induced anorexia was not affected by blockade of OT receptors. In a separate immunocytochemical study, OT-positive terminals were found closely apposed to GLP-1-positive perikarya, and central infusion of OT activated c-Fos expression in GLP-1 neurons. These findings implicate endogenous GLP-1 receptor signaling as an important downstream mediator of anorexia in rats after activation of central OT neural pathways.

scholarly journals Paraventricular Thalamic Control of Food Intake and Reward: Role of Glucagon-Like Peptide-1 Receptor Signaling

2017 ◽  
Vol 42 (12) ◽  
pp. 2387-2397 ◽  
Author(s):  
Zhi Yi Ong ◽  
Jing-Jing Liu ◽  
Zhiping P Pang ◽  
Harvey J Grill
Keyword(s):  
Food Intake ◽  
Receptor Signaling ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

Central glucagon-like peptide 1 receptor-induced anorexia requires glucose metabolism-mediated suppression of AMPK and is impaired by central fructose

2013 ◽  
Vol 304 (7) ◽  
pp. E677-E685 ◽  
Author(s):  
Melissa A. Burmeister ◽  
Jennifer Ayala ◽  
Daniel J. Drucker ◽  
Julio E. Ayala
Keyword(s):  
Food Intake ◽  
Glucose Metabolism ◽  
Dependent Manner ◽  
Anorectic Effect ◽  
Dependent Inhibition ◽  
Glycolytic Inhibitor ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Amp Activated Protein Kinase ◽  
Mediated Reduction

Glucagon-like peptide-1 (GLP-1) suppresses food intake via activation of a central (i.e., brain) GLP-1 receptor (GLP-1R). Central AMP-activated protein kinase (AMPK) is a nutrient-sensitive regulator of food intake that is inhibited by anorectic signals. The anorectic effect elicited by hindbrain GLP-1R activation is attenuated by the AMPK stimulator AICAR. This suggests that central GLP-1R activation suppresses food intake via inhibition of central AMPK. The present studies examined the mechanism(s) by which central GLP-1R activation inhibits AMPK. Supporting previous findings, AICAR attenuated the anorectic effect elicited by intracerebroventricular (icv) administration of the GLP-1R agonist exendin-4 (Ex-4). We demonstrate that Ex-4 stimulates glycolysis and suppresses AMPK phosphorylation in a glucose-dependent manner in hypothalamic GT1-7 cells. This suggests that inhibition of AMPK and food intake by Ex-4 requires central glucose metabolism. Supporting this, the glycolytic inhibitor 2-deoxyglucose (2-DG) attenuated the anorectic effect of Ex-4. However, icv glucose did not enhance the suppression of food intake by Ex-4. AICAR had no effect on Ex-4-mediated reduction in locomotor activity. We also tested whether other carbohydrates affect the anorectic response to Ex-4. Intracerebroventricular pretreatment with the sucrose metabolite fructose, an AMPK activator, attenuated the anorectic effect of Ex-4. This potentially explains the increased food intake observed in sucrose-fed mice. In summary, we propose a model whereby activation of the central GLP-1R reduces food intake via glucose metabolism-dependent inhibition of central AMPK. We also suggest that fructose stimulates food intake by impairing central GLP-1R action. This has significant implications given the correlation between sugar consumption and obesity.

scholarly journals Hindbrain glucagon-like peptide-1 neurons track intake volume and contribute to injection stress-induced hypophagia in meal-entrained rats

2016 ◽  
Vol 310 (10) ◽  
pp. R906-R916 ◽  
Author(s):  
Alison D. Kreisler ◽  
Linda Rinaman
Keyword(s):  
Food Intake ◽  
Potential Role ◽  
Liquid Diet ◽  
Neural Activation ◽  
Intracerebroventricular Injection ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
Diet Intake ◽  
Published Research ◽  
Diet Type

Published research supports a role for central glucagon-like peptide 1 (GLP-1) signaling in suppressing food intake in rodent species. However, it is unclear whether GLP-1 neurons track food intake and contribute to satiety, and/or whether GLP-1 signaling contributes to stress-induced hypophagia. To examine whether GLP-1 neurons track intake volume, rats were trained to consume liquid diet (LD) for 1 h daily until baseline intake stabilized. On test day, schedule-fed rats consumed unrestricted or limited volumes of LD or unrestricted volumes of diluted (calorically matched to LD) or undiluted Ensure. Rats were perfused after the test meal, and brains processed for immunolocalization of cFos and GLP-1. The large majority of GLP-1 neurons expressed cFos in rats that consumed satiating volumes, regardless of diet type, with GLP-1 activation proportional to intake volume. Since GLP-1 signaling may limit intake only when such large proportions of GLP-1 neurons are activated, a second experiment examined the effect of central GLP-1 receptor (R) antagonism on 2 h intake in schedule-fed rats. Compared with baseline, intracerebroventricular vehicle (saline) suppressed Ensure intake by ∼11%. Conversely, intracerebroventricular injection of vehicle containing GLP-1R antagonist increased intake by ∼14% compared with baseline, partly due to larger second meals. We conclude that GLP-1 neural activation effectively tracks liquid diet intake, that intracerebroventricular injection suppresses intake, and that central GLP-1 signaling contributes to this hypophagic effect. GLP-1 signaling also may contribute to satiety after large volumes have been consumed, but this potential role is difficult to separate from a role in the hypophagic response to intracerebroventricular injection.

Differential Importance of Glucose-Dependent Insulinotropic Polypeptide vs Glucagon-Like Peptide 1 Receptor Signaling for Beta Cell Survival in Mice

2009 ◽  
Vol 137 (6) ◽  
pp. 2146-2157 ◽  
Author(s):  
Adriano Maida ◽  
Tanya Hansotia ◽  
Christine Longuet ◽  
Yutaka Seino ◽  
Daniel J. Drucker
Keyword(s):  
Beta Cell ◽  
Cell Survival ◽  
Receptor Signaling ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1

scholarly journals The common hepatic branch of the vagus is not required to mediate the glycemic and food intake suppressive effects of glucagon-like-peptide-1

2011 ◽  
Vol 301 (5) ◽  
pp. R1479-R1485 ◽  
Author(s):  
Matthew R. Hayes ◽  
Scott E. Kanoski ◽  
Bart C. De Jonghe ◽  
Theresa M. Leichner ◽  
Amber L. Alhadeff ◽  
...  
Keyword(s):  
Food Intake ◽  
Vagal Afferents ◽  
Oral Glucose ◽  
Afferent Fibers ◽  
The Common ◽  
Vagal Afferent ◽  
Glucagon Like Peptide ◽  
Glucagon Like Peptide 1 ◽  
And Control ◽  
Hepatic Branch

The incretin and food intake suppressive effects of intraperitoneally administered glucagon-like peptide-1 (GLP-1) involve activation of GLP-1 receptors (GLP-1R) expressed on vagal afferent fiber terminals. Central nervous system processing of GLP-1R-driven vagal afferents results in satiation signaling and enhanced insulin secretion from pancreatic-projecting vagal efferents. As the vast majority of endogenous GLP-1 is released from intestinal l-cells following ingestion, it stands to reason that paracrine GLP-1 signaling, activating adjacent GLP-1R expressed on vagal afferent fibers of gastrointestinal origin, contributes to glycemic and food intake control. However, systemic GLP-1R-mediated control of glycemia is currently attributed to endocrine action involving GLP-1R expressed in the hepatoportal bed on terminals of the common hepatic branch of the vagus (CHB). Here, we examine the hypothesis that activation of GLP-1R expressed on the CHB is not required for GLP-1's glycemic and intake suppressive effects, but rather paracrine signaling on non-CHB vagal afferents is required to mediate GLP-1's effects. Selective CHB ablation (CHBX), complete subdiaphragmatic vagal deafferentation (SDA), and surgical control rats received an oral glucose tolerance test (2.0 g glucose/kg) 10 min after an intraperitoneal injection of the GLP-1R antagonist, exendin-(9–39) (Ex-9; 0.5 mg/kg) or vehicle. CHBX and control rats showed comparable increases in blood glucose following blockade of GLP-1R by Ex-9, whereas SDA rats failed to show a GLP-1R-mediated incretin response. Furthermore, GLP-1(7–36) (0.5 mg/kg ip) produced a comparable suppression of 1-h 25% glucose intake in both CHBX and control rats, whereas intake suppression in SDA rats was blunted. These findings support the hypothesis that systemic GLP-1R mediation of glycemic control and food intake suppression involves paracrine-like signaling on GLP-1R expressed on vagal afferent fibers of gastrointestinal origin but does not require the CHB.

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