Pancreatic atrophy follows bile-induced acute pancreatitis in the rat.

The late course of bile-induced acute experimental pancreatitis was studied in alcoholic and non-alcoholic rats. Addition of alcohol to the drinking water did, however, not influence any of the factors (see below) studied. Six hours after induction of pancreatitis the animals displayed a sixfold increase of S-amylase levels. The late mortality in the whole group of animals was 19% after 6 weeks and 71% after 12 weeks. Rats surviving 6 weeks had a marked reduction of pancreatic wet weight and of pancreatic protein, amylase, phospholipase A2, and S-glucose as compared with healthy controls. S-amylase was similar in all groups studied after 6 weeks. At light microscopy similar changes were seen after 6 and 12 weeks--that is, extensive atrophy of the exocrine pancreas with preserved islets of Langerhans. Only slight fibrosis and slight increase of inflammatory cells were seen, and no protein plugs were detected. The normal liver architecture was generally preserved, but pancreatic rats showed various degrees of bile duct proliferation. Although the morphologic findings do not correspond well with those seen in human chronic pancreatitis, we feel that they represent an integrated late phenomenon of the bile-induced pancreatitis per se, even though partial obstruction of the bile-pancreatic duct may be a co-factor.