Experimental Chronic Gastric Ulcer

It is comparatively easy to produce experimentally acute ulcers in animals, and as far as gross and microscopic examinations go they resemble the same conditions in man. Common to all ulcers so produced, however, is the fact that they heal rapidly, healing being complete in the great majority of cases in from two to three weeks. In the human chronic ulcer, however, hyperacidity is present in at least half the cases, and it seemed to us, then, that if we added this factor to experimental acute ulcer, chronicity might be induced. Furthermore, it is a well-known clinical fact that stomachs with partial pyloric obstruction generally show hyperacidity, or, what is probably synonymous, hypersecretion; consequently we might induce hyperacidity experimentally by partially obstructing the pylorus and later in the same animals cause acute ulcers. To this end we tied a heavy silk ligature around the pylorus of dogs, just tight enough