Splanchnic neural regulation of pancreatic polypeptide release in the isolated perfused human pancreas

The isolated perfused human pancreas was employed as a model in which electrical stimulation of the celiac mixed neural bundle was performed in the presence and absence of selective neural antagonists. Stimulation of the celiac neural bundle in the presence of hyperglycemia resulted in augmentation of pancreatic polypeptide release. Cholinergic stimulation appears to predominate, whereas beta-adrenergic fibers stimulate pancreatic polypeptide-cell secretion, and alpha-adrenergic fibers inhibit pancreatic polypeptide release. During euglycemia, both cholinergic stimulation and gastric inhibitory polypeptide infusion resulted in a marked release of pancreatic polypeptide. These stimulatory effects were additive, which suggests a linked hormonal and neural mechanism of pancreatic polypeptide release after a meal. In this in vitro human model, our data confirm that the splanchnic innervation of the pancreas has a potent regulatory role in pancreatic hormone release in man.