THE LEVEL OF THE ZYMOGEN GRANULE PROTEIN GP2 IS ELEVATED IN A RAT MODEL FOR ACUTE-PANCREATITIS

Background/Aims: GP2 is the major membrane protein in pancreatic zymog en granules. It is linked to the membrane via a glycosyl-phosphatidyli nositol linkage. After cleavage, a significant fraction of GP2 becomes soluble. The present study assessed whether GP2 is a useful serum mar ker for acute pancreatitis. Methods: Using an anti-GP2 monoclonal anti body, an enzyme-linked immunosorbent assay was developed to measure th e serum levels of GP2 in rats with cerulein-induced acute pancreatitis . Results: The anti-GP2 antibody was specific because it did not cross -react with uromodulin, a structurally similar protein to GP2, or to p rotein extracts from nonpancreatic tissues. Eight hours after the indu ction of pancreatitis, the serum levels of amylase, lipase, and GP2 pe aked. Peak GP2 levels were 4.2 times higher than those of controls. At 24 hours, GP2 was still 70% of the peak level, whereas amylase and li pase were 5.5% and 0.5%, respectively, of their peak levels. Conclusio ns: GP2 may serve as a potentially valuable marker for clinical acute pancreatitis.