Stress, the adrenergic hypothalamovagal pathway, and the aetiology of chronic duodenal ulceration.

In the rat, stress activates the hypothalamus causing central adrenergic discharge with delivery of an alpha-adrenergic stimulus by the adrenergic hypothalamovagal pathway to the stomach. This stimulus controls intragastric blood flow and 5-HT release. In rats stressed pharmacologically by administration of intraperitoneal reserpine (0.1 mg/kg), the stimulated pathway releases gastric 5-HT which in turn significantly increases gastric acid secretion. Administration of intramuscular reserpine (0.1 mg/kg) every 24 hr for six weeks significantly (p less than 0.001 by Wilcoxon matched pairs signed-rank test) increased the basal acid output of the rat stomach (12 mumol/h +/- 0.5 vs 38.1 mumol/h +/- 2.4, mean +/- SEM) and produced duodenal ulceration in 83.3% of animals. Vagotomy completely protected the rat stomach against these effects. The data show that prolonged stress in the rat stimulates gastric acid secretion and produces duodenal ulceration.