[An electron microscopical study on the pathogenesis of taurocholate-induced acute pancreatitis]

Electron microscopical and immunoelectron microscopical techniques were employed to investigate the pathogenesis of sodium taurocholateinduced acute pancreatitis. It was demonstrated that the necrosis of pancreatic acinar cells was associated with specific intracellular vacuolation. A continuous course of vacuole formation from zymogen granules was observed. There were of ten several vacuoles inside one acinar cell, and most of the vacuoles were distributed among zymogen granules. These vacuoles contained large amounts of filamentous materials, which were proved to be pancreatic digestive enzymes by immunoelectron microscopical labelling for alpha-amylase and able to digest and disrupt the circumferential organelles. The results of this study suggest that the necrosis of acinar cells was caused by the activation of digestive zymogen inside zymogen granules. As trypsin is the only enzyme which could activate all the digestive zymogen, and trypsinogen is the sole zymogen capable of autoactivation, it is suggested that the autoactivation of trypsinogen plays an important role in the pathogenesis of acute pancreatitis.