CHANGES IN EXTRAHEPATIC BILIARY MOTILITIES WITH EMESIS IN DOGS

To investigate changes in motility of the extrahepatic biliary system associated with emesis, we measured the volume of the gallbladder and now resistance through the sphincter of Oddi, as well as antral and du odenal contractilities before and during retching in decerebrate paral yzed dogs. Motilities of the gallbladder, sphincter of Oddi, duodenum and antrum were enhanced with most episodes of fictive retching elicit ed by stimulation of the central part of the severed dorsal, as well a s the ventral trunk of the thoracic vagus nerve. These enhanced motili ties persisted until the end of retching. Motilities of the sphincter of Oddi and duodenum were sometimes transiently depressed at the begin ning of retching. This depression in the sphincter continued for only 13 +/- 1.0 s, while the gallbladder contraction continued for 65 +/- 3 .4 s. Motilities were rarely enhanced by vagal stimulation when retchi ng was not elicited. These changes in motilities were abolished by bil ateral vagotomy. The serum gastrin level was increased just after and 10 min after retching only when the ventral vagal trunk remained intac t, while the plasma cholecystokinin level was not changed with retchin g. These results suggest that bile evacuation is interrupted with emes is despite contraction of the gallbladder during retching, since the s phincter of Oddi also contracts simultaneously.