Establishment and characteristics of an animal model for isolated pancreatic trauma.

BACKGROUND: There is not any stable, repeatable, and clinically simulated animal model of isolated pancreatic trauma been established as yet. The aim of our study is to establish a small animal model that mimics the pathophysiology of isolated pancreatic blast trauma and to study the features of traumatic condition in the model.
METHODS: Rats were divided into three groups: calibrate group, impact group, and control group. The pancreas in the impact group was injured by BIM-III model of the biotical impact machine with the impact pressures of 800 kPa, 600 kPa, 400 kPa, 200 kPa, and 100 kPa. The mortality, intra-abdominal structural changes, amylase (AMS) and lipase (LPS) activities of serum, and pathologic alterations of the pancreas were examined at 24 hours after trauma. We especially observed these changes and the variation of proliferation index in the rats impacted with 400 kPa pressures after 6 hours, 24 hours, 72 hours, and 7 days.
RESULTS: Pancreatic edema, hemorrhage, cell necrosis, and vacuolization were found accompanied with marked increase in serum AMS and LPS. Severity of pancreatic histologic injury was associated with the impact pressure level and varied over time in the 400-kPa group. Applying 400 kPa impact pressure could be able to provide ideal research samples. Pancreatic trauma also induced compensatory proliferation of pancreatic cells.
CONCLUSION: A practical animal model of isolated pancreatic blunt trauma could be established under 400 kPa pressures. It is ideal for further pathologic and therapeutic study. The combined determination of serum AMS and LPS, particularly the dynamic variation of these enzymes, might assist the diagnosis and prognosis of pancreatic trauma. Further research should focus on the promotion of the cellular regenerative response.