Parietal Cell Kinetics after Administration of Omeprazole and Ranitidine in the Rat

Abstract

Background: This study aimed at determining the turnover rate of parietal cells after inhibition of acid secretion. Methods: Rats were given omeprazole (80 μmol/kg) by gavage once daily or ranitidine (1200 μmol/kg) by osmotic minipump for 5 days. Control rats received saline only. All rats were also given ³H-thymidine by osmotic minipumps. The animals were killed, 5,14,28, or 56 days after the start of the ³H-thymidine infusion. After formaldehyde fixation by perfusion through the aorta, light microscopic autoradiography was carried out on plastic sections of the oxyntic mucosa to determine the labeling index of the parietal cells. Results: The average turnover rate in the control rats was calculated to be 0.61% per day, corresponding to a mean turnover time of 164 days. In the rats given inhibitors of acid secretion, the turnover rates did not differ significantly from those of the control group. Conclusion: Inhibition of gastric acid secretion did not significantly change the turnover rate of the parietal cells.

Key Words:

• Cell kinetics
• gastric mucosa
• omeprazole
• parietal cells
• ranitidine
• rat