Morphological Changes of Pancreatic Ducts in Otsuka Long-Evans Tokushima Fatty Rats

Abstract

To determine if pancreatic ductal changes characteristic of chronic pancreatitis occur in male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and to elucidate the 3-dimensional structure of the pancreatic ducts in those rats. Male OLETF rats aged 10, 20, and 40 weeks were used. The pancreas was injected with a 120% barium sulfate suspension into the pancreatic ducts, after which radiograph images of the injected pancreas were taken using radiography of the soft parts. Conventional fixed pancreatic tissues were observed by the use of light and scanning electron microscopy, whereas corrosion casts of the pancreatic ducts were observed by the use of scanning electron microscopy. In 20- and 40-week-old male OLETF rats, deletion of acini and formation of tubular complexes and tortuous or helical, deformed, dilated pancreatic ducts were found, whereas the inner surfaces of pancreatic ducts had many craterlike depressions and long cilia. Male OLETF rats demonstrated the same morphological changes in pancreatic ductal lumina and histological changes in pancreatic tissues as the rats were subjected to pancreatic duct ligation. These results suggested that increased pancreatic duct pressure occurs in male OLETF rats and induces the chronic pancreatitis-like lesions, including the above-mentioned findings.