Does high pancreatic duct pressure compromise the duct mucosal barrier function to pancreatic exocrine proteins?

The effect of duct pressure on the barrier function of the pancreatic duct mucosa to both activated and nonactivated pancreatic exocrine enzymes was studied in a feline model. The cat main pancreatic duct was perfused from the tail to the head of the gland with rat pancreatic juice at high duct pressure (40 cm H2O). In a first experiment, nonactivated pancreatic juice was perfused. Analysis of the juice for loss of fluid volume (measurement by weight) and for loss of individual proteins (two-dimensional isoelectric focusing/sodium dodecyl sulphate gel electrophoresis, reversed phase-high performance liquid chromatography) after duct passage showed that pancreatic secretions were completely recovered from the duct lumen. In another experiment, applying the same pressure, the duct was perfused with activated pancreatic juice. Morphologic analysis showed a preservation of the pancreatic duct mucosal integrity immediately after duct perfusion and absence of pancreatic inflammatory lesions 24 h after duct passage. We conclude that the pancreatic duct mucosa is impermeable to the leakage of pancreatic exocrine proteins from the duct lumen at duct pressure < or = 40 cm H2O. Flow of activated pancreatic juice along the pancreatic duct at duct pressure < or = 40 cm H2O does not cause acute pancreatitis. These data do not support the hypothesis that leakage of pancreatic juice from the duct lumen caused by high intraductal pressure due to duct obstruction initiates acute pancreatitis.