Free amino acids in basal and vagally stimulated gastric secretion.

The concentrations of the individual free amino acids were determined in one hour fraction of basal secretion and peak hydrogen ion secretion following stimulation with 2-deoxy-D-glucose (2-DG) (group I) or insulin (group II). Group I consisted of 9 patients with duodenal ulcer having hypersecretion of gastric acid as determined by histamine test; 7 patients with duodenal ulcer who underwent truncal vagotomy and had insulin test performed two weeks after the operation formed group II. The total concentration of free amino acids was similar in basal and in stimulated gastric juice in both groups. Also the concentrations of the individual amino acids did not change significantly after stimulation. There was, however, a significant increase following stimulation in the output of amino acids both in group I and in group II. This increase was parallel to that in the volume of gastric juice, which suggests that a definite amount of free amino acids is always present in the gastric juice, and that the secretion of these acids is not under vagal control.