Effects of motilin on gastric and pancreatic secretion in dogs.

13-norleucine motilin (13-nle-motilin), a synthetic analogue of motilin, infused intravenously in graded doses (range: 1.5 to 100 mug/kg-h) produced a dose-dependent increase in basal gastric acid and pepsin secretion and in pancreatic bicarbonate and protein secretion in conscious dogs provided with gastric and pancreatic fistula and Heidenhain pouches. When infused in a constant dose against a background stimulation with pentagastrin, histamine or a peptone meal, 13-nle-motilin inhibited both acid and pepsin secretion from the main stomach and the Heidenhain pouch. It also inhibited dose-dependently secretin-induced pancreatic bicarbonate secretion. Since motilin is released by duodenal acidification, it may be involved in the feedback mechanism controlling gastric and pancreatic secretion.