Effects of antisecretory agents on parietal cell structure and H/K-ATPase levels in rabbit gastric mucosa in vivo.

The effect of inhibition of acid secretion on parietal cell morphology and the concentration of H,K-ATPase alpha-subunit protein was determined by electron microscopy and western blotting. Omeprazole or famotidine alone or in combination were used. Control animals showed a morphological stimulation index (0 = resting, 1.0 = fully stimulated) of 0.60; omeprazole treatment (1 mg/kg, twice a day) resulted a stimulation index of 0.63, famotidine injection (20 mg/kg twice a day) an index of 0.11, famotidine infusion (0.2 mg/hr) for five days an index of 0.38, and the combination of omeprazole and famotidine injection twice a day gave an index of 0.02. No change in the frequency of degenerating or damaged parietal cells was observed in any of the groups. In control animals, the number of lysosomes was 0.9/cell, with famotidine 1.8 and with omeprazole 5.6/cell. H/K-ATPase levels fell by about 25% with omeprazole and rose by about 23% with famotidine.