Sequential Changes of the Autonomic Nervous System in the Development of Cysteamine-induced Duodenal Ulcer, Histochemical and Quantitative Studies

We studied how the autonomic nervous system participated in the develop-ment of experimental duodenal ulcers due to cysteamine hydrochloride. Sym-pathetic fibers showed a slight increase in activities in the duodenal mucosa 1 h after cysteamine administration, and a marked decrease thereafter. The release of noradrenaline (NA) into the blood was suggested. Of the activities of para-sympathetic fibers, true cholinesterase activities, that are concerned with secre-tions, began to increase 1 h after cysteamine administration, which was observed most notably around the Brunner's glands in the duodenal submucosa, peaked at 8h, and then decreased or disappeared at 24h when ulcer formation was established. Pseudo cholinesterase activities that are concerned with motor func-tion, decreased over time with a resulting decrease in gastroduodenal move-ments and emptying. Meanwhile, it was confirmed by estimation of NA and cholinesterase (ChE) by means of a fluorescent histochemical study. The above findings suggest that, though the sympathetic and parasympathetic systems play their roles with a complicated interrelationship in the development of cysteamine-induced duodenal ulcers, sympathetic fibers are initially depressed, and ulcera-tion develops and advances under the parasympathetic dominance. In other words, the development of ulcers seems to depend more on the parasympathetic system than on the sympathetic system.