Changes in the antral mucosal pepsin in dogs with chronic ulcer: pathogenesis of cinchophen ulcer.

All of the dogs given continuous injection of 100 mg/kg sodium cinchophen for 21 days developed chronic ulcers in the pyloric portion of the stomach. Those dogs given cinchophen exhibited a definite increase in gastric pepsin secretion. Readings of gastric mucosal pepsinogen showed a significant high concentration both in the fundic and pyloric gland area in the cinchophen-treated animals. As the injections were continued, the gastric mucosa-juice peptic activity ratio (MJPR) in the fundic gland area become low. These results do not point to pathological changes in the fundic gland area. The mean pH value of the surface of antral mucosa varied greatly from dog to dog and was slightly higher than normal. In the dog which had chronic ulcers in the antral portion, the antral mucosal pepsinogen concentration become eight times higher than that seen in the control animals. The incidence and chronicity of the cinchophen gastric ulcers were related to the local pepsin increase adjacent to the lesions. The origin of pepsin which appeared in the antral mucosa and cinchophen ulcerogenesis were discussed.