ACUTE-PANCREATITIS IS NOT A CAUSE OF CHRONIC-PANCREATITIS IN THE ABSENCE OF RESIDUAL DUCT STRICTURES

It has been shown that intraductal injections of bile salts into the b ile-pancreatic ducts of dogs or rats were immediately followed by acut e hemorrhagic pancreatitis and, some months later, by persisting chron ic pancreatitis. The study described in this article was designed to t est the assumption that these chronic lesions were due to ductal stric tures secondary to the toxic effect of bile salts. The bile-pancreatic ducts of 100 rats were injected with 0.2 ml of a solution containing 4 muM Na taurodeoxycholate and 0.2 muM trypsin. The 66 survivors were killed at intervals from 1 day to 2 months following the induction of acute pancreatitis. Four to six sections were done in the first series , and serial 15-mum sections of the entire pancreas were taken from ra ts surviving 2 months. These showed that from the sixth day on, the la rgest ducts draining pathological areas were obstructed by fibrosis. D istal to this obstruction, intralobular ducts were dilated and their e pithelia flattened or atrophied. Acini were atrophied and replaced by peri- and intralobular fibrosis. Lesions were limited to areas drained by obstructed ducts, with the rest of the parenchyma being normal. We conclude that in experimental animals, as in human beings, chronic le sions that persist after acute pancreatitis are due to duct obstructio n, not to acinar necrosis.