Pituitary adenylate cyclase activating polypeptide (PACAP) redistributes the blood within the pancreas of anesthetized rats

Regul Pept. 1996 Jul 5;63(2-3):123-8. doi: 10.1016/0167-0115(96)00032-8.


The aim of the study was to evaluate the effects of pituitary adenylate cyclase activating polypeptide-38 (PACAP-38) on splanchnic blood flow in anesthetized rats. For this purpose, either PACAP-38 dissolved in saline or saline alone was injected intravenously 5 (10 nmol/kg body weight (bw) PACAP-38) and 30 min (5 or 10 nmol/kg) before measurements. The blood flow to the whole pancreas, islets, duodenum and colon was then measured with a microsphere technique. The higher dose of PACAP-38 slightly increased blood glucose concentrations at both 5 and 30 min after administration, whereas the lower had no effect. Both doses of PACAP-38 induced a transient initial decrease in mean arterial blood pressure. The lower dose of PACAP-38 decreased fractional islet blood flow 30 min after administration, but did not affect the other blood flows. The higher dose of the peptide (10 nmol/kg bw) caused an increase in whole pancreatic blood flow at both 5 and 30 min after administration, whereas islet blood flow was only increased at the former time. At both time points PACAP-38 redistributed the blood flow within the pancreas in favour of the exocrine pancreas. This resulted in a decreased fractional islet blood flow, i.e., the fraction of whole pancreatic blood flow diverted through the islets. At 5 min after PACAP-38 administration duodenal blood flow was decreased, whereas after 30 min no effects on duodenal or colonic blood flow were observed. Administration of a VIP antagonist intravenously (20 nmol/kg bw) decreased the PACAP-38-induced pancreatic blood flow increase and intrapancreatic redistribution. When only the VIP antagonist was given both pancreatic and islet blood decreased in concert. It is concluded that administration of PACAP-38 induces a blood flow increase in the pancreas, preferably in the exocrine parts of the gland, by actions mediated by PACAP-38 receptors shared with VIP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blood Circulation / drug effects
  • Blood Glucose / drug effects
  • Blood Pressure / drug effects
  • Body Weight / drug effects
  • Male
  • Molecular Sequence Data
  • Neuropeptides / pharmacology*
  • Pancreas / drug effects*
  • Peptides / chemistry
  • Peptides / pharmacology
  • Pituitary Adenylate Cyclase-Activating Polypeptide
  • Pituitary Gland / enzymology
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
  • Receptors, Pituitary Hormone / metabolism*
  • Receptors, Vasoactive Intestinal Peptide / antagonists & inhibitors
  • Receptors, Vasoactive Intestinal Peptide / metabolism
  • Vasoactive Intestinal Peptide / pharmacology
  • Vasodilator Agents / pharmacology


  • Adcyap1 protein, rat
  • Blood Glucose
  • Neuropeptides
  • Peptides
  • Pituitary Adenylate Cyclase-Activating Polypeptide
  • Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide
  • Receptors, Pituitary Hormone
  • Receptors, Vasoactive Intestinal Peptide
  • Vasodilator Agents
  • Vasoactive Intestinal Peptide