Graded experimental acute pancreatitis: monitoring of a renewed rabbit model focusing on the production of interleukin-8 (IL-8) and CD11b/CD18.

Objective: To establish and monitor a rabbit model of graded severity of acute pancreatitis to test the hypothesis that interleukin-8 (IL-8) and the adhesion molecule complex CD11b/CD18 are involved in the development of systemic complications in severe acute pancreatitis.

Methods: Acute pancreatitis induction in rabbits by duct ligation with or without infusion of 5.0% or 0.5% chenodeoxycholic acid or 0.9% saline. Control animals underwent laparotomy. The animals were monitored biochemically, histologically and immunohistochemically.

Result: Increased serum levels of IL-8, tumour necrosis factor alpha (TNF-alpha), amylase and lipase were found in the chenodeoxycholic acid groups when compared with the saline, duct-ligated or control groups. Leukopenia, hypocalcaemia, and hyperglycaemia were marked in the 5.0% chenodeoxycholic acid group as compared to the saline, duct-ligated and control groups. Histologically, the 5.0% chenodeoxycholic acid group manifested a significant degree of pancreatic necrosis and neutrophil infiltration. The lungs of these animals showed acute lung injury and a significant up-regulation of CD11b/CD18. IL-8 was produced in pancreatic acinar and ductal cells. A significantly large output of ascitic fluid was seen in the 5.0% chenodeoxycholic acid group.

Conclusion: The rabbit models of acute pancreatitis are reliable in that enzymatic and histological evidence of acute pancreatitis with or without systemic complications developed. IL-8 is produced locally in pancreatic acinar and ductal cells and significantly increased in peripheral blood during severe but not mild pancreatitis. The expression of the adhesion molecule complex CD11b/CB18 is significantly increased in lung tissue during severe acute pancreatitis with acute lung injury. IL-8 and CD11b/CB18 are involved in the pathogenesis of severe acute pancreatitis but not of mild oedematous pancreatitis.