Effects of Active Amines on Development of Stress Ulcers : Review of Noradrenalin, 5-Hydroxytryptamine and Histamine Levels in Brain and Gastric Wall of Restrained and Cold Exposed Rats

Acute hemorrhagic gastroduodenal ulcers are frequently induced by various types of stress. With the purpose of studying the central nervous system factors and gastric mucosal local factors involved in the development of such ulcers, Wistar strain rats were subjected to restraint and cold exposure for 120 minutes, and the intragastric pH, and the noradrenalin, 5-hydroxytryptamine and histamine contents in the brain and gastric wall were measured over time, and the following results were obtained.
1. The intragastric pH decreased with time up to 120 minutes, but the difference with the pre-restraint value was not significant.
2. At 60 minutes after restraint when the ulcerogenic rate became markedly increased, of the amines in the brain, the noradrenalin content showed a significant decrease, while 5-hydroxytryptamine increased significantly, but the histamine value failed to show any significant change.
3. Of the amines in the gastric wall, the histamine level decreased significantly after 30 minutes, and the 5-hydroxytryptamine value showed a significant decrease after 60 minutes.

On the basis of the above findings, it is assumed that the effects of gastric acid on the development of acute hemorrhagic gastroduodenal ulcers are small. However, it is considered that of the amines in the brain, the changes in values of noradrenalin and 5-hydroxytryptamine, and of these in the gastric wall, the changes in 5-hydroxytryptamine and histamine levels have important implications.