Peptides and food intake
- 1Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
- 2Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- 3Centro de Investigación Biomédica en Red Fisiopatología Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food intake, whereas the other subpopulation coexpresses pro-opiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript that inhibits food intake. AgRP antagonizes the effects of the POMC product, α-melanocyte-stimulating hormone (α-MSH). Both populations project to areas important in the regulation of food intake, including the hypothalamic paraventricular nucleus, which also receives important inputs from other hypothalamic nuclei.
Keywords: peptides, orexigenic, ghrelin, anorexigenic, insulin
Citation: Sobrino Crespo C, Perianes Cachero A, Puebla Jiménez L, Barrios V and Arilla Ferreiro E (2014) Peptides and food intake. Front. Endocrinol. 5:58. doi: 10.3389/fendo.2014.00058
Received: 06 January 2014; Accepted: 09 April 2014;
Published online: 24 April 2014.
Edited by:Anca Dana Dobrian, Eastern Virginia Medical School, USA
Reviewed by:Subrata Chakrabarti, The University of Western Ontario, Canada
Brian M. Shewchuk, Brody School of Medicine at East Carolina University, USA
Copyright: © 2014 Sobrino Crespo, Perianes Cachero, Puebla Jiménez, Barrios and Arilla Ferreiro. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Eduardo Arilla Ferreiro, Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Madrid E-28871, Spain e-mail: firstname.lastname@example.org