In the present study, morphological changes
of the exocrine pancreas in rats after pancreatic duct
ligation were examined with light microscopy
(hematoxylin-eosin, TUNEL, and PCNA staining) and
scanning electron microscopy in order to elucidate the
effects of increased pancreatic duct pressure. On the fifth
day after pancreatic duct ligation, ductular proliferation,
periductal fibrosis, and disappearance of acini were
obserbed. TUNEL and PCNA staining demonstrated
many apoptotic acinar cells and proliferating ductal cells
immediately after ligation, which reached a maximal
number on the 2nd or 3rd day. Tortuous or helical
interlobular pancreatic ducts with inner surfaces
containing many crater-like depressions and long cilia
were found after ligation. These changes were almost
identical to those observed in the pancreatic tissue of
model chronic pancreatitis rats, WBN/Kob rats, and
stroke-prone spontaneously hypertensive (SHRSP) rats.
In summary, the morphological changes observed
after pancreatic duct ligation were similar to those of
chronic pancreatitis, therefore, the characteristic changes
of pancreatic ducts observed in chronic pancreatitis may
be caused by increased pancreatic duct pressure