Influence of various factors and drugs on cysteamine-induced duodenal ulcers in the rat.

The cysteamine-induced duodenal ulcer reported by Selye et al. was investigated and the optimum conditions for the production of ulcers in rats were established. A single subcutaneous administration of cysteamine between 200 and 500 mg/kg produced ulceration in a dose-dependent manner in the duodenum within 18 hr. Female and older rats were more susceptible to cysteamine than male and younger ones, respectively. Atropine methylbromide inhibited duodenal ulcers induced by cysteamine dose-dependently and pyloric ligation immediately prior to cysteamine dosing completely inhibited ulceration. Tegragastrin or bethanechol increased the severity of cysteamine-induced ulceration. These data suggest that gastric juice may play an important role in the pathogenesis of cysteamine-induced ulcers. The present study provided an excellent animal model for studying the mechanism of duodenal ulcers and screening of antiulcer agents.