[Effect of long-term administration of antisecretary drugs on rat gastric histamine synthesis and acid secretion--compare with omeprazole and cimetidine].

To investigate the effect of 6 weeks administration of proton pump inhibitor (omeprazole) and H2-receptor antagonist (cimetidine) on gastric histamine synthesis and acid secretion, we studied experimentally in the rat stomach. Then gastric mucosal histamine concentration, histidine decarboxylase (HDC) activity and serum gastrin concentration, and HDC positive cell number were examined in time-course. The 6 weeks administration of omeprazole caused more increase of HDC positive cells than cimetidine. After cessation of administration with omeprazole, high plasma gastrin level immediately reduced. However the increase of gastric mucosal HDC activity and histamine concentration were prolonged, compared with cimetidine. These findings suggest to affect differently between omeprazole and cimetidine on gastric acid secretion after cessation of long-term treatment.