Pancreatic Response to Repeated Secretin Stimulation in Dogs

By cannulation of the major pancreatic duct in 5 anesthetized dogs with chronic Thomas type duodenal fistulas, pancreatic juice has been collected after repeated injections of equal, submaximal doses of secretin (Vitrum). The intervals between injections has been 60 min and 120 min. It is shown that the pancreatic response to secretin decreases when intervals between injections are 60 min. When the intervals are 120 min there is no decrease. The possible explanations of this phenomenon is discussed. The most likely assumption seems to be that the gland in a certain period following secretin stimulation has a reduced sensitivity to secretin, indicating a “relative refractory period”.