Comparison of the agonist activity of impromidine (SK & F 92676) in anaesthetized rabbits and on the rabbit isolated fundic mucosa.

1 The actions of impromidine in vivo and in vitro have been compared on gastric acid secretion. In both preparations impromidine was more potent than histamine. 2 There were no statistically significant differences between the maximum responses to impromidine and histamine in vivo or in vitro although in vitro the maximum response to impromidine was only 67% of that to histamine. In vivo the maximum response to impromidine was significantly less than the maximum response to histamine plus mepyramine. 3 The results are discussed in the light of recent findings.