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 cholecystokininoctapeptide (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 100 ng/kg of CCK-OP. Results. CCK-OP at 20 ng/kg produced sphincter relaxation followed by contracting in the controls, but produced no changes after duodenectomy. CCK-OP at 100 ng/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 20 ng/kg of CCK-OP require the presence of the duodenum; (2) early contractions of the sphincter induced by 100 ng/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.