Gastric Secretory Response to Different Doses of Carbachol and Pentagastrin in Man

In 6 healthy students, the gastric secretion of acid, pepsin, and IF was measured during one hour at basal conditions, and during one hour of stimulation with 0.01 mug/kg/h and thereafter during one hour of stimulation with 0.1 mug/kg/h of pentagastrin. On separate days the same dose of pentagastrin was given in combination with 0.15 mug/kg/h or 1.5 mug/kg/h of carbachol, or stimulation was performed with each of the two doses of carbachol alone. A dose-dependent relationship was found between carbachol and the output of acid, pepsin, and IF. The responses to carbachol were independent of changes in plasma gastrin concentration. The acid- and IF-secretions stimulated by the largest dose of pentagastrin were significantly increased by the largest dose of carbachol, whereas the secretion of pepsin was not. Pentagastrin and carbachol seem to interact by competitive augmentation on the gastric secretion of acid and IF.