Expression of stress proteins heme oxygenase-1 and -2 in acute pancreatitis and pancreatic islet betaTC3 and acinar AR42J cells.

Oxygen-derived free radicals have been implicated in the pathogenesis of acute pancreatitis, yet adaptive responses in the pancreas in vivo to oxidative stress remain poorly defined. We have investigated expression of the stress protein heme oxygenase in the intact pancreas of rats with caerulein-induced pancreatitis and in cultured pancreatic acinar and islet cell lines. Expression of inducible heme oxygenase-1 (HO-1) in the pancreas in vivo was enhanced 12-24 h after induction of pancreatitis. In murine islet (betaTC3) and rat acinar (AR42J) pancreatic cells, H2O2, methyl viologen, cadmium chloride and diethylmaleate enhanced HO-1 expression in a dose- and time-dependent manner, without altering expression of constitutive HO-2. Enhanced expression of HO-1 in the pancreas in vivo and pancreatic islet and acinar cells may contribute to cellular defences against oxidative stress associated with acute pancreatitis.