The effect of truncal vagotomy on the intestinal release of secretin, cholecystokinin (CCK), and gastrin, and on their action on pancreatic secretion, has been studied in conscious dogs with chronic gastric and pancreatic fistulas. Vagotomy caused a substantial reduction of pancreatic exocrine secretion in response to the intraduodenal instillation of hydrochloric acid, amino acids, and oleic acid soap, but did not affect pancreatic secretion induced by exogenous secretin or CCK. This suggests that vagal innervation plays a permissive role in the release of these hormones from the intestinal mucosa but does not interact with them at the level of the pancreatic secretory cells. Vagotomy resulted in a substantial increase in the basal serum gastrin level, but it impaired gastrin release caused by intestinal stimulants, which indicates that the release of intestinal gastrin may also be under cholinergic control.
Konturek SJ, Becker HD, Thompson JC. Effect of Vagotomy on Hormones Stimulating Pancreatic Secretion. Arch Surg. 1974;108(5):704-708. doi:10.1001/archsurg.1974.01350290068011