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 acu te pancreatitis to test the hypothesis that interleukin-8 (IL-8) and the ad hesion molecule complex CD11b/CD18 are involved in the development of syste mic complications in severe acute pancreatitis. Methods Acute pancreatitis induction in rabbits by duct ligation with or wi thout infusion of 5.0% or 0.5% chenodeoxycholic acid or 0.9% saline. Contro l animals underwent laparotomy. The animals were monitored biochemically, h istologically and immunohistochemically. Result Increased serum levels of IL-8, tumour necrosis factor alpha (TNF-al pha), amylase and lipase were found in the chenodeoxycholic acid groups whe n compared with the saline, duct-ligated or control groups. Leukopenia, hyp ocalcaemia, and hyperglycaemia were marked in the 5.0% chenodeoxycholic aci d group as compared to the saline, duct-ligated and control groups. Histolo gically, the 5.0% chenodeoxycholic acid group manifested a significant degr ee of pancreatic necrosis and neutrophil infiltration. The lungs of these a nimals showed acute lung injury and a significant up-regulation of CD11b/CD 18. IL-8 was produced in pancreatic acinar and ductal cells. A significantl y 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 enz ymatic and histological evidence of acute pancreatitis with or without syst emic complications developed. IL-8 is produced locally in pancreatic acinar and ductal cells and significantly increased in peripheral blood during se vere but not mild pancreatitis. The expression of the adhesion molecule com plex CD11b/CB18 is significantly increased in lung tissue during severe acu te pancreatitis with acute lung injury. IL-8 and CD11b/CB18 are involved in the pathogenesis of severe acute pancreatitis but not of mild oedematous p ancreatitis. (C) 1999 Lippincott Williams & Wilkins.