Gastrointestinal Hormones Controlling Energy Homeostasis and Their Potential Role in Obesity

DE FRANCESCO, PABLO N.; PERELLO, MARIO; ANDREOLI, MARÍA F

Textbook of Energy Balance, Neuropeptide Hormones, and Neuroendocrine Function

Springer

Lugar: Cham; Año: 2018; p. 183 - 203

Gastrointestinal (GI) hormones are produced by specialized enteroendocrine cells that are located in the epithelial layer throughout the whole GI tract. All together, these cells form the biggest endocrine organ of the body and produce the largest number of hormones. Enteroendocrine cells are characterized as being either open- or closed-type. Open-type cells display direct contact with the GI lumen and are able to sense molecules present in the luminal content, such as nutrients, which play a major regulatory role on hormone secretion. In contrast, closed-type cells lack connection with the lumen because their apical side is enclosed by epithelial cells. Closed-type cells are mainly regulated by molecules coming from the GI capillaries or by autonomic activity.The action of the GI hormones described in this chapter is mediated through G protein-coupled receptors (GPCRs), and mediate their actions in the peripheral tissues as well as in the central nervous system (CNS). In addition to integrating GI functions, some GI hormones play an important role in the regulation of body energy homeostasis. The mechanisms by which some GI hormones regulate energy homeostasis are diverse and involve control of meal size, meal timing, hedonic aspects of eating, and adiposity as well as the regulation of the meal-related glycemia. Here, we focus on four GI hormones: ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide tyrosine-tyrosine (PYY), which likely play a relevant role in the control of the energy homeostasis. In addition, we briefly review the role of oxyntomodulin (OXM), pancreatic polypeptide (PP), and somatostatin (SST), which may also play a role on energy balance.