Effect of pentagastrin on histamine output from the stomach in patients with duodenal ulcer.

The role of histamine in acid secretion is controversial. Improvements in the techniques of histamine assay allow a better assessment of the relationship of histamine to acid secretion. Patients with duodenal ulcers were studied to determine the mucosal histamine responses to pentagastrin stimulation to relate the appearance of histamine in the gastric juice to acid production during stimulation, and to detect changes in the plasma histamine concentration during pentagastrin stimulation. There was a mean 27% fall (range 0-60%) in mucosal histamine concentration after pentagastrin. The output of histamine into gastric juice closely paralleled acid output in peak output acid duration. The histogram profiles of acid and histamine were similar in shape. In contrast with previous studies, plasma histamine concentration was found to rise during peak acid secretion (mean rise 65%). There was no relationship between initial mucosal histamine concentration and acid secretion or maximal gastric juice histamine. The association of histamine and gastric acid release found in these studies was so close that a functional relationship may be presumed. Our data are compatible with the hypothesis that pentagastrin acts on the parietal cell indirectly by causing histamine release in the gastric mucosa, which in turn releases acid from the parietal cells.