The effect of ranitidine on gastric acid secretory response curves to histamine, pentagastrin or bethanechol in the dog with a heidenhain pouch

Abstract
The H2-receptor antagonists ranitidine and cimetidine were tested against gastric secretory dose-response curves to histamine, pentagastrin and bethanechol in the Heidenhainpouch dog. Histamine-induced gastric secretion was antagonized in a competitive manner by both ranitidine and cimetidine, but ranitidine was approximately 8 times more potent than cimetidine. Pentagastrin-induced secretion was markedly reduced by ranitidine and cimetidine but this antagonism was not competitive in nature. Bethanechol-induced gastric secretion was slightly reduced by both drugs. These findings are discussed in relation to he physiological control of gastric secretion.