The Influence of the Autonomic Nervous System on the Onset of Stress Ulcers : Mainly on the Changes of Biogenic Amine Contents in Brain and Stomach in Cold Restrained Rats

Acute gastroduodenal ulcers are frequently induced by the stress of various type. With a view to examining the influence of the autonomic nervous system on the mechanism of onset of stress ulcers, splanchnicotomy or vagotomy was performed in rats and loaded cold restraint stress for 120 minutes. Subsequently, the contents of biogenic amines in brain and stomach were determined. Further observations on the pH value of the gastric jujce and the microvasculature of the gastric mucosa were made, and the following results were obtained.

1. The incidence of gastric ulcers in the control and splanchnicotomized group markedly increased in 60 minutes after stress, whereas in the vagotomized group, it did not show an increase even 120 minutes.

2. As for amines in brain, NA content significantly decreased in 60 minutes, while 5-HT content increased significantly. These changes were fixed, regardless of the cutting of the autonomic nerve or not.

3. Regarding amines in stomach, HA and 5-HT content significantly decreased in the control and splanchnicotomized group.

4. The pH value in gastric juice did not decreased significantly with time up to 120 minutes, in all groups.

5. Impairment on microcirculation in gastric mucosa were suggested in the control and splanchnicotomized group after stress.

Judging from these findings, it was assumed that, for the onset of stress ulcers, NA and 5-HT in brain were associated, whereas in stomach, HA and 5-HT isolated by the vagotonia, rather than the NA isolated by the sympathicotonia, were associated. It was further presumed that stress ulcers are caused by the impairments on the microcirculation on gastric mucosa due to the isolation of HA and 5-HT, rather than the increase in the acidity of gastric juice.