Enzymatic and histological alterations in the isolated perfused rat pancreas under conditions of oxidative stress

Background. Oxidative stress is a relevant event in the pathogenesis of acute pancreatitis. Investigations in vivo are limited because of the complexity of the organism and the short half-life of free radicals. The isolated perfused rat pancreas could be useful for investigations in the early phase of acute pancreatitis especially under conditions of oxidative stress.

Methods. External perfusions of the pancreatic glands of Wistar rats were carried out using a modified Krebs-Ringer buffer including an additive of the detergents Triton X-100 and a perfusion including hydrogen peroxide (0.0012%) or tert-butylhydroperoxide (0.0042%) or xanthine oxidase (0.1 U/ml). Changes in amylase, lipase, LDH in the portal outflow fluid and for histological alterations were analyzed.

Results. Damage to pancreatic parenchyma using Triton X-100 was indicated by increased levels of pancreatic enzymes in the perfusion medium. During perfusion with hydrogen peroxide or tert-butylhydroperoxide we found no changes in pancreatic enzymes in the portal outflow. In contrast, perfusion with xanthine oxidase induced a significant elevation in lipase and amylase in the effusion fluid after 30 min. We found a significant increase in edema in the hydrogen peroxide and in the xanthine oxidase group. Focal necroses of the pancreatic parenchyma were detected in all groups of oxidative stress.

Conclusions. The isolated perfused rat pancreas is a valuable experimental model for investigating the early phase of pathophysiology in acute pancreatitis, for instance, the effect of oxidative stress as an early event in acute pancreatitis. Using hydrogen peroxide tert-butylhydroperoxide or xanthine oxidase, only xanthine oxidase was able to induce a typical elevation in the pancreas enzymes in the effusion fluid.