In vitro study on histamine-induced cyclic adenosine monophosphate production in ulcer patients with different antisecretory responses to ranitidine

Failure of acid suppression by H 2 receptor antagonists has been observed in some patients with peptic ulcer diseases. The reasons for the drug resistance are unknown. In the present study, the effects of histamine and the H 2 receptor antagonist ranitidine/CAS 66357-35-5) on cyclic adenosine monophosphate/AMP) production was investigated using intact cells from gastric mucosal biopsies derived from patients with adequate (AR) and inadequate (IR) antisecretory response to ranitidine. The classification of AR and IR was performed by intragastric nocturnal pH-monitoring