Gastric secretory response to graded doses of pentagastrin alone or in combination with carbacholine in unoperated duodenal ulcer patients.

Dose-response studies of pentagastrin-stimulated secretion were performed in 6 unoperated duodenal ulcer patients. On different days pentagastrin was given in doses of 0.15, 1.5, and 15 mug/kg/hr, either alone or in combination with carbacholine, 2 mug/kg/hr. There were no significant differences between mean acid or pepsin outputs or mean volumes of gastric juice after infusion of pentagastrin alone or pentagastrin plus carbacholine at any dose step of pentagastrin. The dose of pentagastrin required to elicit half maximal acid output (Km) and the calculated maximal acid output (Vmax) were the same for pentagastrin alone and pentgastrin plus carbacholine. Thus, carbacholine did not increase the sensitivity of the parietal cells to pentagastrin in the unoperated duodenal ulcer patients.