Stimulatory effect of secretin on pancreatic polypeptide in diabetic patients

In diabetic patients plasma levels of pancreatic polypeptide (PP) increased four fold after intramuscular injection of secretin (50 CHRU, Eisai Co.) in spite of the lack of response of plasma insulin, plasma glucagon and blood glucose levels. In control subjects, PP levels did not change significantly after secretin injection. Since pancreatic polypeptide has is known to have an inhibitory effect on the exocrine pancreas, the present study suggests the possibility that disturbed function of the exocrine pancreas in diabetic patients could be related to the remarkable response of PP to secretin-stimulation.