Effect of cimetidine treatment on parietal and chief cell sensitivity to histamine and on catabolism of histamine in duodenal ulcer patients.

Gastric acid and pepsin output in response to a low and a maximal dose of histamine was studied before and 60 h after cessation of 4 weeks of cimetidine treatment, 1 g/day, in 11 duodenal ulcer patients. Plasma histamine concentrations were measured in eight patients and the urinary excretion of intravenously injected 14C-histamine and its metabolites in two patients. Acid and pepsin output in response to the low dose of histamine as a percentage of the maximal response was on average 41.3% +/- 4.4% (S.E.M.) and 46.3% +/- 3.5% before treatment and 40.4% +/- 4.8% and 38.8% +/- 4.5% after cessation of treatment, respectively (p greater than 0.10). Thus, a course of treatment with cimetidine does not influence the sensitivity of the parietal and chief cells to histamine stimulation in duodenal ulcer patients. No significant change of plasma histamine concentrations and of catabolism of radiolabelled histamine was observed after cessation of cimetidine treatment.