Influences of ulcerogenic stimulations in the stomach with the clamping ulcers in rats.

Ulcerogenic stimulations such as histamine and restraint water immersion stress were given to rats after the gastric ulcers were made by the clamping method. Development of the stress and histamine ulcers were distinctly inhibited after the clamping ulcers were made, and this inhibition reached a maximum at the 7th clamping ulcer day and lowered gradually thereafter. In control rats, the stress and histamine ulcers usually develop in the lesser curvature, but in animals with the clamping ulcers they develop in the greater curvature where the clamping ulcer was made. The histological changes of the stress ulcers in the stomach with the clamping ulcer were slighter compared with those of the control (without clamping ulcers) rats. Furthermore, the relationships between the development of the stress ulcers and the changes of the uronic acid content in the stomach were observed. The uronic acid content increased after the clamping ulcer was made and reached a maximum at the 7th clamping ulcer day. Thereafter it began to decrease and returned to the normal level. From the results of the studies, it was strongly suggested that the mechanism of inhibition to development of the stress ulcers might be attributed to an increase of acid mucopolysaccharide in the gastric wall after the clamping ulcer was induced.