2013 年 2 巻 1 号 p. 69-75
The gastrointestinal tract secretes several peptide hormones that regulate food intake by transmitting signals to the central nervous system related to energy homeostasis. Abnormalities in the regulation of food intake are manifested as overeating or refusal of food (apastia) that can cause obesity, leanness, and other metabolic disorders. Obesity, in particular, is the root cause of various lifestyle diseases, and, therefore, is a major health problem that should be overcome. Eating disorders are considered to be caused by a breakdown in the food intake regulatory system of the central nervous system and the peripheral nervous system; much is still unknown about signal transmission, and the secretion of gastrointestinal peptides and their receptor mechanisms. However, studies have shown that amylin, glucagon, insulin, pancreatic polypeptide, and enterostatin secreted by the pancreas function as food intake suppressors in peripheral tissues. In addition, leptin excreted by adipocytes is also known to function as a food intake suppressor. This review focuses on the gastrointestinal peptides that are related to food intake. This issue introduces anorexic peptides, cholecystokinin, peptide YY, glucagon-like peptide-1 (GLP-1), bombesin/gastrin-releasing peptide (BN/GRP), or oxyntomodulin (OXM), and orexigenic peptide ghrelin. Moreover, it also summarizes how these peptides function to maintain homeostasis in an organism.