A functional description of the canine choledochoduodenal flutter valve.

Forward- and reverse-opening pressures of the choledochoduodenal junction were measured in anesthetized, vagotomized dogs. Mean reverse-opening pressures were found to be significantly greater in most cases including those following the intraductal administration of vasoactive agents which are known to significantly influence mean forward-opening pressures. The polypeptides CCK-PZ and CCK-C8 were ineffective in reducing mean forward-opening pressures regardless of the route of administration. Previously published observations have indicated that mean forward-opening pressures are also unaffected by nervous activity. It is concluded that the canine choledochoduodenal junction possesses the physical and functional properties of a passive flutter valve during duodenal relaxation.