Scanning electron microscopic observation of pancreatic ducts in WBN/Kob rats.

To elucidate changes of pancreatic ducts in chronic pancreatitis, we observed pancreatic tissues with light microscopy and scanning electron microscopy, and corrosion casts of pancreatic ducts with scanning electron microscopy, in male WBN/Kob rats, considered a spontaneously occurring chronic pancreatitis model. At 3 months of age, hemorrhage and increased fibrosis were found in part of the pancreatic tail. After 3 months of age, pancreatic ductal lumina exhibited a winding form and inner surfaces showed long cilia and crater-like depressions. Fibrous tissues gradually extended into exocrine tissues and islets after 6 months of age. Most pancreatic ductal lumina developed a helical form with many deep depression at 14 months of age. It is suggested that increased pancreatic ductal pressure causes these findings.