Cholecystokinin regulates satiation independently of the abdominal vagal nerve in a pig model of total subdiaphragmatic vagotomy

Ad libitum liquid meal intake (mean ± SEM) was similar in sham and vagotomized pigs (4180 ± 435 and 3760 ± 810 g/meal). Intake increased by about 20% after blockade of CCK1 receptors, independently of the abdominal vagal nerve. Food intake did not increase after blockade of GLP-1 receptors. Blockade of CCK1 and GLP-1 receptors increased circulating CCK and GLP-1 concentrations in sham pigs only, suggesting the existence of a vagal reflex mechanism in the regulation of plasma CCK1 and GLP-1 concentrations. Vagotomy decreased acetaminophen absorption and changed glucose, insulin, CCK and GLP-1 concentrations indicating a delay in gastric emptying. Our data show that at liquid feeding, satiation is decreased effectively by pharmacological blockade of CCK1 receptors. We conclude that regulation of liquid meal intake appears to be primarily regulated by CCK1 receptors not located on abdominal vagal nerve endings.