[Mechanism of action of fentolamin on the gastric secretion]

Thirty-three experiments were made on mongrel dogs operated on according to Basov, with the use of phentolamine, pilocarpine, atropine, histamine and their combinations. It was established that administration of histamine gives rise to an increase in gastric secretion, provided the animals are pretreated with phentolamine or with combined pilocarpine and phentolamine. Histamine-induced gastric secretion considerably decreases, provided the animals are pretreated with atropine and ceases almost completely after administration of combined atropine and phentolamine. It is concluded that the stimulating effect of phentolamine on gastric secretion is caused by an increase in the sensitivity of H2-receptors and cholinoreceptors under blockade of the alpha-adrenoreactive systems.