Xanthine oxidase activity in mouse pancreas: effects of caerulein-induced acute pancreatitis.

The development of acute pancreatitis involves a number of pathophysiological changes which result in pancreatic tissue damage. Data from several models of acute pancreatitis suggest that the in vivo conversion of the enzyme xanthine dehydrogenase to xanthine oxidase may cause tissue damage by the subsequent generation of oxygen-derived free radical products. In the present studies, acute pancreatitis was induced in mice by the administration of supramaximal secretory doses of caerulein, a cholecystokinin analogue. Pancreatic xanthine oxidase activity was observed to occur in the dehydrogenase form in both control and treated mice. Artifactual conversion to the oxidase form could be induced by exclusion of 2-mercaptoethanol and phenylmethylsulfonyl fluoride from the buffer during tissue preparation. These data indicate that no significant conversion of xanthine dehydrogenase to oxidase is associated with this model of acute pancreatitis in mice.