EFFECTS OF LONG-TERM ADMINISTRATION OF HISTAMINE H2 RECEPTOR ANTAGONIST AND H+/K+ATPase INHIBITOR ON THE REGULATION KINETICS OF GASTRIC ACID SECRETION BY GASTRIN

Histamine H2 receptor antagonist (H2-RA) and H+/K+ ATPase inhibitor (PPI) were used in treating chronic peptic ulcers and acute gastric mucosal lesions. Recently, in treating peptic ulcers, long-term administration of these drugs developed the pyloric gland gastrin cell hyperplasia and also increased the serum gastrin concentration, etc.Therefore, in order to verify the occurrence of these problems after administration of the drugs, the author has focused on studying the relationship between the serum gastrin concentration and histological changes in the antral mucosa. In this study, male Wistar rats weighing 180-200g were used and the following were assessed : 1) changes of G-cell counts in the pyloric gland 2) gastric acid secretion and 3) changes in the status of gastrin secretion following long-term administration of H2-RA and PPI given for 4 or 8 weeks were evaluated. After 4 weeks administration of these drugs, gastrin cell proliferation was seen in the rats. In the groups given triple doses of these drugs, hypergastrinemia was obtained at the same time. On the other hand, when administration of the drugs was stopped for the same period, gastrin cell proliferation and hypergastrinemia were disappeared. It can therefore be concluded that there is the potential for recovery when administration of these drugs is stopped for a period equal to that of their administration. In treating peptic ulcers it is emphasized to remember that the changes in the gastric : mucosa and gastric acid secretion are reversible.