A technique has been developed for repeated, direct, manometric study of the canine choledochoduodenal junction in conscious animals. The junction is characterized by a zone of elevated pressure interposed between the duodenum and common bile duct whose motor activity distinguishes it from these adjacent structures. Atropine sulfate administration resulted in a decrease in pressure in the junctional zone suggesting that a cholinergic mechanism is partly responsible for the maintenance of resting pressure in the canine choledochoduodenal junction.
Crispin JS, Choi YW, Wiseman DGH, Gillespie DJ, Lind JF. A Direct Manometric Study of the Canine Choledochoduodenal JunctionThe Effect of Atropine. Arch Surg. 1970;101(2):215-218. doi:10.1001/archsurg.1970.01340260119019