Effects of synthetic human pancreatic polypeptide, synthetic bovine pancreatic polypeptide, and the C-terminal hexapeptide on pancreatic somatostatin and glucagon secretion in the rat.

Synthetic human pancreatic polypeptide stimulated pancreatic somatostatin secretion by isolated rat islets and by the isolated perfused rat pancreas. In contrast, synthetic bovine pancreatic polypeptide and the C-terminal hexapeptide had no effect on somatostatin secretion. Synthetic human pancreatic polypeptide had only a mild stimulatory effect on glucagon secretion at the highest concentration of the peptide used (2.2 x 10(-6) M0 and in the presence of 16.7 mM glucose.