Release of Hyaluronan and Laminin into Pancreatic Secretions

Abstract

Background: Development of fibrosis characterizes chronic pancreatitis. As it results from deposition of extracellular matrix (ECM) proteins such as hyaluronan (HA) or laminin, the release of these ECM components into blood or pancreatic secretion may be enhanced during the course of chronic pancreatitis. Patients, Material and Methods: Using immunoassays for HA and laminin, the concentration for these ECM components was measured in pancreatic juice and serum samples from 20 patients with and 20 patients without chronic pancreatitis. Pancreatic calculi of varying size and weight obtained from 13 patients with chronic pancreatitis were also examined for the content of ECM components. Tissue samples from normal pancreas and those showing chronic pancreatitis were investigated immunocytochemically with an antibody to HA synthetase (HAS). Results: After stimulation with secretin high levels of ECM components were found in the initial washout period in chronic pancreatitis patients as well as in controls. HA levels, however, were seen seven times higher in patients with chronic pancreatitis (mean ± SEM; 734 ± 301 vs. 95 ± 15 µg/l; p < 0.01). Serum HA levels correlated with the duration of chronic pancreatitis and with the levels of HA in pancreatic juice. HA and laminin were detected in the supernatants of pancreatic calculi (laminin 0.70 ± 0.30 U/l; HA 275 ± 85 µg/l). Immunocytochemically, strong staining for HAS was found in the duct epithelium and in centroacinar cells of chronic pancreatitis specimens. Conclusion: Demonstration of increased amounts of HA in pancreatic juice of chronic pancreatitis patients stimulated with secretin suggests enhanced production of this ECM component in the chronically inflamed pancreas. The source of HA appears to be the pancreatic ductal epithelium.