Pancreatic polypeptide, glucagon and insulin secretion from the isolated perfused canine pancreas

The release of pancreatic polypeptide (PP) by gut hormones, acetyl choline and adrenaline was investigated in an isolated perfused pancreas preparation. PP was potently released by 1 nmol/1 caerulein (186 +/- 12%, p is less than 0.001) and gastric inhibitory peptide (GIP) (211 +/- 31%, p is less than 0.005) as well as by 1 mumol/1 acetyl choline (1097 +/- 59%, p is less than 0.001). A significant two-fold release of PP was also evoked by 1 nmol/1 vasoactive intestinal peptide (VIP) (129 +/- 38%, p is less than 0.02 and gastrin (108 +/- 25% p is less than 0.01). Insulin release, induced by high glucose concentration was enhanced by both GIP (210 +/- 38%, p is less than (0.01) and VIP (48 +/- 5%, p is less than 0.001). In addition GIP enhanced the release of glucagon by 179 +/- 18% (p is less 0.001) at 1.4 mmol/1 glucose and by 127 +/- 24% (p is less than 0.005) at 8.3 mmol/1 glucose. Thus no simple inter-relationship appears to exist between the control of the three circulating islet hormones.