The effects of impromidine and pentagastrin on gastric output of histamine, acid and pepsin in man.

Histamine and hydrogen ion concentrations and peptic activity have been measured in gastric juice in 8 normal subjects during infusion of pentagastrin, pentagastrin plus cimetidine, and impromidine. The stimulation of gastric secretion under all 3 conditions produced an initial increase in histamine concentration and output in gastric juice, which was not sustained. The total stimulated histamine output in one hour was similar with pentagastrin and pentagastrin plus cimetidine, but was significantly higher with impromidine (p less than 0.05), a histamine methyltransferase in normal human gastric mucosa. These results do not support the concept that histamine is the final local common chemostimulator of the parietal cell in man.