Intestinal migration by Hymenolepis diminuta: 5-hydroxytryptamine, vagal stimulation, and intestinal secretions

Abstract

The effects of 5-hydroxytryptamine (5-HT) (administered orally and by duodenal cannulation) and vagal stimulation on the anteriad migration of the adult Hymenolepis diminuta were examined. Surgical restriction of gastrointestinal secretions were done to determine if the effects of 5-HT and vagal stimulation were mediated via gastric or biliopancreatic secretions. Elevation of intraluminal concentrations of 5-HT by duodenal cannulation elicited worm migration via the action of the pancreatic secretions. Oral administration of 5-HT and vagal stimulation elicited migrational responses through additional pathways that did not involve the biliary–pancreatic secretions. 5-HT does not appear to have a direct effect on worm migratory behaviour.