The effect of acute bilateral adrenalectomy on serotonin‐induced inhibition of gastric acid secretion and acute gastric mucosal injury in rats

Serotonin (5-hydroxytryptamine, 5-HT) produces many changes in gastric functional parameters, including the inhibition of gastric acid secretion and changes in mucosal blood flow. Exogenous 5-HT has also been shown to induce gastric erosion. The influence of adrenalectomy on experimental lesions in the rat gastric mucosa remains controversial. The aim of this study was to see the effects of adrenalectomy on pentagastrin stimulated gastric acid secretion in anaesthetized male Wistar rats. Gastric acid was collected via cannulae placed in the stomach. 5-HT (3.5 mumol/kg, i.v.) inhibited pentagastrin stimulated acid output by 54% and produced haemorrhagic gastric lesions with a mean ulcer index of 2 +/- 0.3. Adrenalectomy prevented both 5-HT induced inhibition of gastric acid secretion and mucosal injury. The results suggest that the effects of 5-HT require an intact adrenal gland.