Gastric secretagogue action of ergot alkaloids in the perfused stomach of anesthetized rats

Abstract

The gastric secretagogue action of ergot alkaloids was studied in the perfused stomach of anesthetized rats. Ergometrine dose-dependently increased gastric acid secretion and other ergot alkaloids, methysergide, methylergometrine, ergotamine and dihydroergotamine were also found to stimulate gastric secretion. However, Hydergine and bromocriptine did not influence the basal secretion. The gastric secretagogue action of ergometrine was completely inhibited by atropine and was markedly reduced but not abolished by vagotomy. Intraventricular administration of ergometrine produced an increase of acid secretion. Ergometrine did not affect the blood glucose level while insulin decreased it. The effect of ergometrine was not inhibited by serotonin agonistic or dopamine antagonistic agents. These results suggest that some ergot alkaloids have a gastric secretagogue action mainly due to their central effect in anesthetized rats and these actions cannot be explained by serotonin antagonistic, dopamine agonistic and alpha-adrenergic blocking effects of ergot alkaloids. The mechanism of the secretagogue action of ergometrine was different from that of insulin.