Somatostatin inhibition of basal and carbachol-stimulated gastrin release in rat antral organ culture

Abstract

The effects of somatostatin on gastrin release and total gastrin immunoreactivity were examined under in vitro conditions in rat antral organ culture experiments. Basal antral gastrin release was inhibited by somatostatin. Total culture gastrin contents (culture medium gastrin plus extracted antral mucosal gastrin) at 6 h were reduced significantly by 10−5 M (p < 0.02) and 10−4 M (p < 0.01) somatostatin. Gastrin release into the culture media stimulated by the cholinergic agent, carbachol (10−5 M), was suppressed by somatostatin: at 30 min and 6 h of culture 10−8 M somatostatin inhibited carbachol-stimulated gastrin release by 66% and 54%, respectively, and 10−5 M and 10−4 M somatostatin completely abolished gastrin release. The rate of gastrin release stimulated by carbachol was suppressed significantly by each dose of somatostatin examined (10−8 M to 10−4 M). The present studies indicate that somatostatin inhibits both gastrin secretion by cultured rat antral mucosa and total antral culture gastrin contents, and demonstrate that cholinergically-mediated gastrin secretion is inhibited by somatostatin.