[An experimental study on pancreatitis associated with anomalous junction of the pancreaticobiliary ductal system with special reference to the activation of prophospholipase A2 in bile].

Congenital dilatation of the bile duct is often accompanied by recurrent pancreatitis. Reflux of pancreatic juices into the bile duct through anomalous junction and activation of pancreatic zymogens could be involved in its pathophysiological mechanism. In order to test this hypothesis, a rat model was designed according to Block's method with some modifications, and kinetics of activation of prophospholipase A2 (pro-PLA2) in bile was examined by measuring phospholipase A2 (PLA2) activity and by immunoblot analysis, using anti-rat pancreatic enzyme antibody, by which PLA2 could be separated from its zymogen. Experimental animals were divided into three groups. Group 1; bile and pancreatic juice were mixed under the occlusion of the papilla. Group 2; the occlusion of the papilla and hilus without mixing of both juices was produced. Group 3; simple laparotomy was made. The pro-PLA2 in bile was remarkably activated to its active form in Group 1. In group 2, there was only slight elevation of PLA2 activity which was mostly composed of pro-form. An immunohistochemical study demonstrated localization of PLA2 around necrotic foci in the pancreatic parenchyma in only group 1. These results will support the involvement of PLA2 in the pathogenesis of the pancreatitis.