Simultaneous evaluation of gastric and duodenal ulcers-healing activities of anti-ulcer agents in rats

We investigated the effects of cimetidine, omeprazole and atropine, antisecretory anti-ulcer agents, on the healing of gastric and duodenal ulcers simultaneously induced in the same rats. Furthermore, we examined the effect of histamine, an acid secretory agent, on the healing of both ulcers. When the effects of test drugs were assessed on the 15th day after local application of acetic acid, repeated oral administration of cimetidine (50 and 100 mg/kg twice daily) or omeprazole (25 and 50 mg/kg once daily) markedly accelerated the healing of both gastric and duodenal ulcers. Atropine (10 mg/kg twice daily, p.o.) showed a healing effect on duodenal ulcers only. The repeated subcutaneous administration of histamine (30 mg/kg 3 times daily) apparently delayed the healing of duodenal ulcers but not gastric ulcers. In conclusion, this experimental chronic ulcer model in rats is useful for directly comparing the effects of anti-ulcer drugs on the healing of gastric and duodenal ulcers. In addition, the increase in acid secretion appears to have a greater influence on the delay of ulcer healing in the duodenum than in the stomach.