Effects of Stress Transmission Pathways on Acute Ulcerogenesis in Rats under Cold-Restraint Stress

The effect of autonomic nerve and pituitary-adrenal pathways of stress transmission on stress-induced acute gastric ulceration was studied using splanchnicotomized (Sp), truncal vagotomized (TV) and splanchnicotomized plus vagotomized (Sp + TV) rats. Cold-restraint stress was loaded for 30, 60 and 120 min. With normal rats as a control group, the change in incidence of gastric mucosal lesions, contents of noradrenalin (NA), histamine (HA) and serotonin (5-HT) within gastric mucosa and levels of serum ACTH and 11-OHCS was compared. In the Sp group, there was no significant difference in the NA content before and after stress loading, but the HA content at 30 min after stress loading and the 5-HT content at 60 min were significantly decreased [ 5.0 ± 1.6 μg/g and 30.0 ± 0.6 μg/g, mean ± SD, respectively] as opposed to their respective contents before stress [8.6 ± 1.1 and 4.3 ± 1.1, respectively] [p < 0.01 and p < 0.05], as it did in the control group. The incidence of animals with gastric mucosal lesions amounted to a high rate of 88% at 120 min. On the other hand, in the TV and Sp + TV groups the HA and 5-HT contents underwent no significant decreases until 120 min after stress loading, and the incidences of lesions were suppressed to 13%. In the control group, the serum ACTH level at 30 min and the serum 11-OHCS level at 60 min were significantly increased as compared with their respective values before stress. The levels of serum ACTH and 11-OHCS in the Sp, TV and Sp + TV groups showed similar patterns of changes to those seen in the control group. The results indicate that the pituitary-adrenal pathway exerts a milder effect than the autonomic nerve pathway on acute ulcerogenesis induced by cold-restraint stress.