EFFECT OF SHORT-TERM AND LONG-TERM TREATMENT WITH OMEPRAZOLE ON CELL-CYCLE DISTRIBUTION IN THE GASTRIC-MUCOSA - RESULTS OF A FLOW CYTOMETRIC STUDY

Omeprazole may exert an effect on gastric mucosal proliferation by inh ibiting gastric acid secretion and increasing serum gastrin levels. It may also influence the kinetics of endocrine cells and the oxyntic mu cosa. The aim of the present study was to evaluate the cell cycle in d ifferent gastric compartments following short- (1 month) and long-term (6 months) administration of two different dosages of omeprazole by m eans of a flow cytometric method. We also determined serum gastrin lev els at the same time. No differences in cell cycle distribution of the antrum, body, and fundus were found in the two different dosage group s after 1 month of therapy, considering the synthetic phase (S-phase) of the cell cycle. A statistically significant increase in S-phase was reported after long-term therapy in the mucosa of the fundus and body of the stomach in both groups. Gastrin levels showed no clear correla tion with cell cycle distribution variables. We postulate a proliferat ive adaptation of the oxyntic mucosa to long-term drug administration not mediated by gastrin influence.