IS HISTAMINE ABLE TO MAINTAIN AN AUGMENTED PEPSIN RESPONSE COMPARABLE TO THAT OF PILOCARPINE?

Abstract

A "continuous stimulation" test was used wherein small uniform doses of histamine or pilocarpine were given subcut. every 10 mins. over 7-9 hrs. Under these conditions a uniform vol.-rate and pH of the gastric juice was obtained in 5 dogs with vagotomized total stomach pouches. The samples collected every 20 mins. after the 1st hr. were analyzed for acid and for pepsin by means of the Hb method. Adm. of 0.10 mg. histamine produced twice the vol. response with a significantly greater pepsin output than when 0.025 mg. histamine was similarly given. Pilocarpine (0.20 mg. every 10 mins.) stimulated a vol. response comparable to that of 0.025 mg. histamine. However, the pepsin output was about 5 times as great as when 0.10 mg. histamine was similarly administered. These results were duplicated in condensed expts. wherein the 8-hr. continuous stimulation was divided into 3 periods, employing 2 different levels of dosage. Although pilocarpine is the more potent, in the vagotomized stomach pouch of dogs, histamine acts to stimulate pepsin secretion in the same manner as does pilocarpine.