Although a significant amount of the serotonin (5-hydroxytryptamine) in the body exists in tissue-bound form, predominantly in the mucosa of the gastrointestinal tract, the brain, and to a less extent in the platelets, no definite physiologic role has been assigned to this interesting active amine except in the malignant carcinoid syndrome. Recently, however, serotonin has also been implicated as a physiologic regulatory substance in intestinal motor activity2 and in gastric secretion.1,9
In preliminary experiments in our laboratory it was established that serotonin and serotonin precursor (5-hydroxytryptophane) produce a significant depression of pancreatic secretion in dogs with chronic pancreatic fistulas, suggesting that these substances may also play a physiologic role in the regulation of pancreatic secretion.
The present report deals with further studies of the physiology of pancreatic secretion and specifically of the mechanism of alteration of pancreatic secretion by serotonin.
Successful chronic total pancreatic fistulas were prepared