Gastric mucosal blood flow and pepsin secretion in dogs--stimulation by 13-nle-motilin.

In response to graded doses of intravenous 13-norleucine-motilin (13-nle-motilin)--a synthetic analogue of motilin and biologically equivalent to the natural polypeptide-, gastric mucosal blood flow (GMBF) in canine vagally denervated fundic pouches was studied using the aminopyrine clearance technique. As 13-nle-motilin did not exert any detectable effect on gastric secretion of hydrogen ions, intraluminal instillation of 160 mM HCl was used to provide a pH gradient allowing aminopyrine to move into the pouch lumen. With increasing doses of 13-nle-motilin, GMBF increased to 148% of control values; pepsin secretion - due to augmented pepsin concentration - rose concomitantly. Enhanced pepsin secretion was not accompanied by an increase in cyclic 3',5'-adenosine monophosphate secretion.