Comparison of the effect of PGE 2 and somatostatin on histamine stimulated 14C-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.