Comparison of the effect of PGE2 and somatostatin on histamine stimulated14C-aminopyrine uptake and cyclic AMP formation in isolated rat gastric mucosal cells

In isolated rat gastric cells somatostatin and PGE₂ were compared in respect to their effects on the cAMP system and on the histamine-stimulated H⁺-production, measured by¹⁴C-aminopyrine (¹⁴C-AP) uptake. Like PGE₂ somatostatin activated adenylate cyclase (AC) for all in non-parietal cells. This effect on AC declined in cell fractions with increasing number of parietal cells. Activation of AC or elevation of cellular cAMP and uptake of¹⁴C-AP in response to histamine were inhibited by 10^?9 to 10^?5 mol/l PGE₂ and somatostatin. The results indicate remarkable similarity between somatostatin and PGE₂: both activate a non-parietal cell AC and both inhibit H⁺-production, likely by interfering at the histamine sensitive AC of the parietal cell.