Pancreatic polypeptide and splanchnic blood flow in anesthetized rats

The aim of the study was to evaluate the effects of pancreatic polypeptide (PP) on splanchnic blood flow in anesthetized rats. For this purpose, either PP dissolved in saline (225, 450, or 900 pmol/kg body weight/h) or saline alone was infused at a rate of 2 ml/h for 30 min. Immediately after the infusion the blood flow to the whole pancreas, islets, duodenum, and colon was measured with a microsphere technique. The highest dose of PP caused a small decrease in mean arterial blood pressure. The two lowest doses decreased duodenal blood flow, but did not affect the blood perfusion to the other investigated organs. The highest dose of PP decreased the blood flow to the pancreas, islets, and duodenum, did not affect colonic blood flow. No change in the fraction of whole pancreatic blood flow diverted through the islets could be seen after PP administration. It is concluded that administration of high doses of PP induces a general splanchnic vasoconstriction.