Duodenum is important for the sphincter of Oddi motor response to cholecystokinin octapeptide in conscious dogs

Background We investigated the role of the duodenum in the sphincter of Oddi response to cholecystokinin-octapeptide (CCK-OP), using conscious dogs.Methods In controls, a cannula was inserted into the duodenum opposite the papilla for retrograde manometry. In the duodenectomy group, the entire duodenum was resected, while preserving the papilla, which was implanted into the jejunum, and the cannula was placed. Sphincter motility was recorded after bolus injections of 20 and 100ng/kg of CCK-OP.Results CCK-OP at 20ng/kg produced sphincter relaxation followed by contraction in the controls, but produced no changes after duodenectomy. CCK-OP at 100ng/kg caused strong contractions followed by relaxation in the controls, but caused only contractions after duodenectomy.Conclusions (1) Relaxation and delayed contraction of the sphincter induced by 20ng/kg of CCK-OP require the presence of the duodenum; (2) early contractions of the sphincter induced by 100ng/kg of CCK-OP do not require the duodenum; (3) the duodenum plays an important role in the actions of CCK-OP on sphincter motility.