| Theme |
The Gastrointestinal Tract and Appetite Control : Essential Clinical Knowledge |
| Title |
Anorexigenic Effects of Gastrointestinal Hormones -- the Actions and Roles of Cholecystokinin (CCK) in the Control of Appetite |
| Author |
Naomi Yamaguchi |
Department of Gastroenterology and Hepatology, Saitama Medical Center, Saitama Medical University |
| Author |
Eriko Hosomi |
Department of Gastroenterology and Hepatology, Saitama Medical Center, Saitama Medical University |
| Author |
Kenjiro Hayashi |
Department of Gastroenterology and Hepatology, Saitama Medical Center, Saitama Medical University |
| Author |
Koji Yakabi |
Department of Gastroenterology and Hepatology, Saitama Medical Center, Saitama Medical University |
| [ Summary ] |
Recently, the gastrointestinal hormones have been shown to have important roles in the control of appetite through the brain-gut axis. Their actions induce the sensations of hunger and satiation and determine both the start and duration of the feeding. Among these hormones, CCK was the first discovered hormone with anorexigenic action. CCK is secreted by I-cells in the small intestine, and is mainly induced by the intake of fat and protein. CCK levels rise in blood within 10 to 20 minutes after the start of a feeding. CCK binds to CCK1 receptors localized on afferent vagal nerves, resulting in a stimulation of the neurons situated in the nucleus of the solitary tract (NTS) and the paraventricular nucleus of the hypothalamus (PVN). The stimulation of these satiety centers induces the feeling of satiation and leads to the termination of feeding. The regulation of appetite by CCK takes place at every meals of daily life. The actions of gastrointestinal hormones such as CCK modulate the size and duration of meals and protect animals, including humans, from obesity and nutrition deficiency. The clinical significance of the actions of CCK is still to be elucidated in future studies. |