1. Duodenojejunal intestinal loops in rats were perfused with cholera toxin and the pancreatic and biliary secretory responses studied.
2. Intraluminal cholera toxin induced a significant flow of pancreatic and biliary ñuid and sustained protein (enzyme) secretion in pancreatic juice, in addition to the expected stimulation of mucosal secretion.
3. Intravenously injected cholera toxin failed to elicit a secretory flow from the pancreas and biliary tract.
4. The time-course of the enhanced secretory flow from pancreas and biliary tract after intraluminal cholera toxin corresponds closely to the secretion of intestinal fluid.
5. The results of these studies provide evidence of sustained stimulation of pancreatic and biliary secretions after mucosal exposure to cholera toxin. These observations support the suggestion that secretion from the pancreas and liver may significantly contribute to the total intestinal secretion in cholera.