Short term inhibitory effect of somatostatin on gastric histamine synthesis

Abstract

In this study we investigated the short term effect of somatostatin on histamine synthesis in a cell population isolated from rabbit gastric mucosa and enriched in enterochromaffin-like cells. Somatostatin inhibited basal and gastrin-stimulated histamine synthesis through a dual mechanism involving a decrease in the affinity of histidine decarboxylase (HDC) for its substrate (L-histidine) and a reduction in the number of functional HDC molecules. H- 89 (an inhibitor of cAMP-dependent protein kinase) mimicked somatostatin- induced reduction of HDC affinity, which, on the contrary, was selectively reversed by pertussis toxin (PTX). Furthermore, forskolin was shown to reverse the inhibitory eff..