Numerous studies in man and animals suggest that beta-adrenergic receptors stimulate pancreatic polypeptide (PP) release whereas alpha-adrenergic receptors inhibit PP release. This study was undertaken to further clarify the role of the adrenergic nervous system in regulating PP release. We evaluated the effects of stellatectomy and celiacectomy on resting and meat meal-stimulated PP release in the dog. PP release was studied in three stages--control, poststellatectomy, and poststellatectomy plus celiacectomy in five dogs. The meat meal caused a prompt and prolonged increase in plasma levels of PP. Stellatectomy did not alter the control PP response. However, celiacectomy increased basal and peak PP levels and enhanced the early and late phases of delta-integrated PP release. The data suggest that the celiac and superior mesenteric ganglia are the main source of the adrenergic innervation of the pancreas and that this innervation is primarily an inhibitor of PP release.