Role of gastrin in vagally-stimulated pancreatic secretion

In an attempt to clarify the contribution of antral gastrin to the vaginal stimulation of pancreatic secretion, we have measured the effect of total excision of the antral mucosa on pancreatic secretion induced by electrical vagal stimulation in eight anesthetized dogs. Stimulation was done before excision of the mucosa, and after excision, with and without a gastrin background. Mucosal excision reduced pancreatic volume response to 25% and pancreatic protein response to 32% of the respective responses obtained before excision; gastrin release in response to vagal stimulation was completely abolished. With a gastrin background (0.5 microgram/kg-hr of synthetic human gastrin-17-I), which resulted in serum gastrin concentrations higher than those obtained by vagal stimulation before excision of antral mucosa, the pancreatic volume and protein response showed only partial restoration. These studies provide evidence that vagal pancreatic secretion is only partially gastrin-dependent, and that other antral factors, probably vagally modulated intramural cholinergic pathways, are involved.