Histopathologic difference between chronic pancreatitis animal models and human chronic pancreatitis.

Objectives: There are many experimental models for chronic pancreatitis. However, it remains unclear which animal models of pancreatic fibrosis can be categorized as chronic pancreatitis models. We compared the histologic features of some animal models of pancreatic fibrosis/chronic pancreatitis and chronic pancreatitis in humans.

Methods And Results: Human chronic pancreatitis due to chronic alcohol abuse and unknown etiology showed interlobular fibrosis and a cirrhosis-like appearance. Histopathologically, spontaneous pancreatitis models, WBN/Kob rats and OLETF rats, showed localized/nodular fibrotic lesions, which consisted of swollen, aggregated, atrophic islets of Langerhans; loss of the exocrine parenchyma and hemosiderin deposition that was seldom distributed in the interlobular area. On the other hand, fibrosis in the canine model, which was produced by combining alcohol administration with incomplete pancreatic duct obstruction, was characterized by interlobular fibrosis admixed with a cirrhosis-like appearance very similar to that in human chronic pancreatitis.

Conclusion: Most experimental models for chronic pancreatitis, except alcohol administration combined with other procedures such as incomplete pancreatic duct obstruction, are different from human chronic pancreatitis.