Pancreatic Secretion by Nonparallel Exocytosis: Potential Resolution of a Long Controversy

The idea that pancreatic digestive enzyme secretion can occur in a nonparallel manner has been controversial because of its presumed incompatibility with the exocytosis secretory mechanism. Correlation and regression analysis of enzyme output by the rabbit pancreas after it is stimulated with cholecystokinin and chymodenin revealed that digestive enzymes are secreted in a highly linked fashion, compatible with exocytosis and with nonparallel secretion. Thus, exocytosis and nonparallel secretion are not contradictory processes, but rather nonparallel secretion is due to exocytosis from heterogeneous sources within the pancreas.