Augmented parietal cell sensitivity to histamine after cimetidine treatment in healthy subjects.

Basal and histamine-stimulated (0.4, 1.6, 6.4, and 25.6 micrograms . kg-1 h-1 of histamine dihydrochloride) gastric secretion was studied in 2 groups of 10 healthy young subjects before and 60 h after cessation of 4 weeks of cimetidine treatment, 1 g/day. Basal acid and pepsin outputs were not significantly different before and after treatment. After cessation of treatment acid output in response to the two lowest doses of histamine had increased significantly, whereas the output in response to the two highest doses of histamine was unchanged. The results are consistent with a hypersensitivity of the parietal cells to histamine stimulation after cessation of cimetidine treatment in healthy subjects. Pepsin output in response to histamine stimulation and catabolism of exogenous histamine were not influenced by treatment with cimetidine.