Abstract
Experimental ulcers induced by various kinds of stress have been used as a model for the gastric and duodenal ulcers which are the typical ones in psychosomatic diseases. The restrained water immersion method is the most popular. We have used this method in rats, monkeys and dogs and observed the successive gastric mucosal changes using a gastrofiberscope without sacrificing the animals. The gastrofibenscope idebtified what kinds of changes occurred, where they began and how long they lasted. We could also estimate the effects of some psychotropic drugs in these same animals. We presented actual methos and results, and discussed our findings. Naturally occurring human gastric ulcers are somewhat different from experimental ulcers in animals, especiallu the chronic ones. It is difficult to induce exparimental chronic ulcers in animals which will resemble those found in man. Using the gastrofiberscope we injected 8% acetic acid into the gastric mucosa of dogs. With this method, we could induce ulcers which require lengthy healing periods. These ulcers, however, are essentially different from those found in man. We pointed out limits of experimental ulcers and considered the various involved.
