Effect of porcine pancreastatin on endocrine function of canine pancreas

Controversial results concerning the modulation of insulin release with pancreastatin prompted us to investigate the effect of this peptide upon the endocrine function of the pancreas using an in situ perfusion method in dogs. Administration of porcine pancreastatin into the pancreaticoduodenal artery in a dosage of 0.34 micrograms/kg of body weight during arginine infusion increased slightly plasma insulin and lowered minimally plasma glucagon in the pancreaticoduodenal vein. Pancreastatin infusion in a dosage of 500 ng/min did not modify glucose-induced insulin release and glucagon suppression by glucose. Theophylline infusion induced a slight increase in plasma insulin and glucagon in the pancreaticoduodenal vein. Pancreastatin infusion accelerated slightly these changes in plasma insulin and glucagon following theophylline infusion. From the present experiment it is concluded that porcine pancreastatin did not inhibit glucose-induced insulin release from the canine pancreas, inconsistent with the first report on insulin release from the rat pancreas. Alternatively, porcine pancreastatin rather stimulated insulin release during arginine infusion or following theophylline administration.