Augmented vagal release of antral gastrin by 2-deoxyglucose after fundic vagotomy in dogs

To study the relation between gastrin released by vagal excitation and the secretion of H+ and pepsin under various conditions, central vagal excitation was induced by 2-deoxyglucose (2DG) in doses of 50, 100, and 200 mg/kg body wt given as a single intravenous injection in seven gastric fistula dogs, three with fundic vagotomy and four with intact vagi. Serum gastrin increased linearly with dose doubling in both groups but was twice as high in the vagotomized dogs. Total acid output for 3 h was related linearly to integrated gastrin output in both groups, but the slope, H+/gastrin, was 10 times steeper in the vagally intact dogs (330 vs. 34 mueq/pg gastrin-ml-30 min) and pepsin output almost 20 times greater [5,400 peptic units (PU) vs. 296 PU]. Acidification of the antrum to pH 1.2-1.4 eliminated the gastrin response to 2DG in both groups of dogs. Atropine (100 microgram/kg iv) reduced serum gastrin in the vagotomized and increased it in the intact dogs. Atropinization uncovers stimulation by 2DG by pathways that do not involve muscarinic cholinergic receptors. Stimulation by both pathways is suppressible by acid. We conclude that fundic vagotomy removes an inhibitor of vagal gastrin release.