Stimulation of human pepsin output by tropical hydrochloric acid.

Pepsin secretion is stimulated by the back-diffusion of acid across the mucosa of the vagally denervated canine pouch. If back-diffusion is enhanced by damage, pepsin secretion increases. The current study investigates whether this mechanism exists in man. The stomach of normal human volunteers were irrigated for 1 hour with either buffer of 0.01 N HCl, 1 hour with 0.2 N HCl, and a final hour with buffer or 0.01 N HCl. During the middle hour both the concentration and output of pepsin increased three- or fourfold. From these studies it appears that the human gastric mucosa contains a mechanism similar to the dog's which results in the stimulation of pepsin secretion when exposed to acid. This mechanism could be of etiologic significance in gastric ulcer disease, which has been shown to be associated with increased gastric-mucosal permeability.