The release of pancreatic polypeptide by exogenous CCK in man and dog

4 healthy volunteers received commercial 20% pure CCK-33 in 4 consecutive doses of 0.5, 1.0, 2.0, 4.0 IDU/kg/h. blood samples were assayed for pancreatic polypeptide (PP) by radioimmunoassay. Plasma PP concentrations increased stepwise from a basal level of 67 +/- 15 pmol/l to a maximum of 198 +/- 46 pmol/l (p less than 0.05). In 4 mongrel dogs with Thomas cannulas, the same doses of 99% pure CCK-33 were successively infused. Plasma PP concentrations rose stepwise with each dose from 44 +/- 7 to 259 +/- 43 pmol/l (p less than 0.02). This rise significantly correlated with pancreatic protein secretion (p less than 0.01). It is concluded that intravenous CCK-33 induces the release of PP in man and in dog, in a dose-dependent manner.