In vivo release of gastrin into human gastric juice.

The release of antral gastrin has been examined in human subjects by infusing saline and albumin into their stomachs. Immunoreactive gastrin (IRG) was present in fasting serum but not in fasting gastric juice. Intragastric infusions of saline and albumin induced small but significant (P less than 0.05) rises in the serum concentrations of IRG. There was no significant difference between the magnitude of the serum gastrin responses to these two stimuli. The stimuli induced a rise in the luminal concentration of IRG which was sixfold greater than that in the serum concentration of IRG. The response to albumin was significantly greater than the response to saline (P less than 0.05). The IRG in gastric juice was chromatographically similar to heptadecapeptide gastrin. The stimuli also released IRG in patients with duodenal ulcers. The magnitude of the release into serum and gastric juice in these patients was significantly reduced by antrectomy (P less than 0.05).