Pancreatic cationic elastase in porcine experimental pancreatitis.

A radioimmunoassay for porcine, cationic, pancreatic elastase (irPE) is described. Normal porcine serum contains only small amounts of irPE (less than 3 micrograms/l). IrPE in serum and peritoneal exudate from 6 pigs with experimental pancreatitis was found mainly in a molecular form corresponding to free pro-enzyme. The presence of alpha 1-, alpha 2-macroglobulin-bound elastase-like enzymatic activity in the peritoneal exudates from pigs with pancreatitis, however, indicates that the proteinase is to some extent released as the active enzyme. In some pigs with pancreatitis, the elastase-like activity against Succ(Ala) in the peritoneal exudates increased during the experiment, arguing for a progressive activation of pro-elastase. Free proteolytic activity was not observed in any of the peritoneal exudates. This low degree of activation of elastase and the fact that the elastase inhibiting capacity is substantially larger than the trypsin inhibiting capacity in serum and biological fluids, leads us to the conclusion that active elastase is not a factor of principal importance in the pathogenesis of proteinase inhibitor consumption and tissue damage in our experimental pancreatitis model.