Effects of omeprazole on the number of immunoreactive gastrin- and somatostatin-cells in the rat gastric mucosa.

The effects of omeprazole--an inhibitor of gastric acid secretion--on gastrin (G)- and somatostatin (D)-cell density in the gastric antral mucosa epithelium in rats were examined, following a 5-day treatment. It was found that omeprazole increased the density of G-cells, whereas it decreased the density of D-cells. That effect was probably independent of hypergastrinaemia, since it could not be blocked by a simultaneous treatment with proglumide--a gastrin receptor blocker. It is concluded that the observed phenomenon is a direct result of a lower gastric acidity, as a consequence of omeprazole treatment.