PATHOPHYSIOLOGICAL ROLE OF SECRETORY TYPE-I AND TYPE-II PHOSPHOLIPASE-A(2) IN ACUTE-PANCREATITIS - AN EXPERIMENTAL-STUDY IN RATS

Background-In human acute pancreatitis two different types of secretor y phospholipase A(2) (PLA(2)) have been found. Aim-To analyse the spec ific pattern of distribution of these PLA(2) activities and their path ophysiological role in experimental acute pancreatitis. Subjects and M ethods-Catalytic activities of secretory type I (pancreatic) and type II (non-pancreatic) PLA(2) and the protein concentration of immunoreac tive pancreatic PLA(2) (IR-PLA(2)) in serum and pancreatic tissue of r ats with cerulein (mild form) and sodium taurocholate (severe form) in duced acute pancreatitis were determined. Results-Cerulein infusion ca used a significant increase in type I PLA(2) activity (p<0 . 01) and I R-PLA(2) protein concentration (p<0 . 01) in serum and pancreas, where as type II PLA(2) activity remained unchanged during the 12 hour obser vation period. Histology showed no significant tissue destruction. In sodium taurocholate induced acute pancreatitis type II PLA(2) activity significantly increased, reaching values over 10-fold higher than con trols (p<0 . 01), whereas IR-PLA(2) protein concentration and type I P LA(2) activity were only marginally increased. In this severe model of acute pancreatitis significantly lower values were detected than in t he control pancreas (p<0 . 002) for PLA(2) activity and IR-PLA(2) prot ein concentration. Histology showed parenchymal and fat necroses with haemorrhage, oedema, and inflammatory cell infiltration. Conclusions-T ype I PLA(2) activity is dependent on the IR-PLA(2) protein concentrat ion in serum and pancreatic tissue. The type II PLA(2) activity is not stimulated by cerulein, which indicates an extra-acinar origin of thi s enzyme. Type II PLA(2) activity is significantly increased in sodium taurocholate induced acute pancreatitis indicating its role in the lo cal necrotising process and involvement in the systemic effects in sev ere acute pancreatitis.