![]() |
|
|
Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada M5S 3E2
2To whom correspondence should be addressed. E-mail: harvey.anderson{at}utoronto.ca.
This study investigated the hypotheses that dietary proteins suppress food intake partly through the glucagon-like peptide-1 (GLP-1) signaling pathway, and that this effect is mediated by products of protein digestion. The GLP-1 receptor agonist, Exendin-4 (Ex-4) (0.5 µg/rat), was given intraperitoneally to male Wistar rats, and food intake was measured when Ex-4 was given alone or with preloads of intact whey and casein proteins, their hydrolysates and amino acid mixtures (0.5 g · 4 mL-1 · rat-1). Both Ex-4 and the preloads suppressed food intake (P < 0.05), but the effect of Ex-4 on food intake was reduced when coadministered with the preloads (P < 0.05). Because the effect of Ex-4 was reduced by the protein hydrolysates and by the amino acid preloads, the results support a role for the end products of protein digestion and GLP-1 release in the suppression of food intake in response to protein ingestion. We concluded that the GLP-1 signaling pathway, activated by the release of products of protein digestion, is another mechanism accounting for the reduction of food intake after protein ingestion.
KEY WORDS: agonist amino acids food intake gut hormone protein
This article has been cited by other articles:
![]() |
M. R. Hayes, K. P. Skibicka, and H. J. Grill Caudal Brainstem Processing Is Sufficient for Behavioral, Sympathetic, and Parasympathetic Responses Driven by Peripheral and Hindbrain Glucagon-Like-Peptide-1 Receptor Stimulation Endocrinology, August 1, 2008; 149(8): 4059 - 4068. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. L. Luhovyy, T. Akhavan, and G. H. Anderson Whey Proteins in the Regulation of Food Intake and Satiety J. Am. Coll. Nutr., December 1, 2007; 26(6): 704S - 712S. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Scott and T. H. Moran The GLP-1 agonist exendin-4 reduces food intake in nonhuman primates through changes in meal size Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2007; 293(3): R983 - R987. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Park, X. Dong, T. L. Fisher, S. Dunn, A. K. Omer, G. Weir, and M. F. White Exendin-4 Uses Irs2 Signaling to Mediate Pancreatic beta Cell Growth and Function J. Biol. Chem., January 13, 2006; 281(2): 1159 - 1168. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Aziz, G. H. Anderson, A. Giacca, and F. Cho Hyperglycemia after protein ingestion concurrent with injection of a GLP-1 receptor agonist in rats: a possible role for dietary peptides Am J Physiol Regulatory Integrative Comp Physiol, September 1, 2005; 289(3): R688 - R694. [Abstract] [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] |
||||
![]() |
G. H. Anderson, S. N. Tecimer, D. Shah, and T. A. Zafar Protein Source, Quantity, and Time of Consumption Determine the Effect of Proteins on Short-Term Food Intake in Young Men J. Nutr., November 1, 2004; 134(11): 3011 - 3015. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. H. Anderson and S. E. Moore Dietary Proteins in the Regulation of Food Intake and Body Weight in Humans J. Nutr., April 1, 2004; 134(4): 974S - 979S. [Abstract] [Full Text] [PDF] |
||||