The effect of serotonin and serotonin antagonists on external pancreatic secretion in dogs

Summary Suppression of external pancreatic secretion in dogs was produced by exogenous serotonin (serotonin creatinine sulfate) despite constant secretin stimulation and despite vagotomy or atropine. Attempts to modify this response, and attempts to modify the similar response to intraduodenal hypertonic feedings, by pretreatment with a number of serotonin antagonists were unsuccessful. Possible mechanisms involved in these pancreatic responses are discussed.