Pancreatic function tests in the rat model of chronic pancreatic insufficiency.

It has recently been shown that the infusion of oleic acid into the rat pancreaticobiliary duct causes a reproducible and long-lasting atrophy of the exocrine pancreas. The effects of this pancreatic atrophy on non-invasive pancreatic function tests have not been fully characterized. This study was undertaken to determine which pancreatic function test was most useful in determining pancreatic insufficiency in this model. Pancreatic insufficiency (PI) was induced in male Wistar rats by oleic acid infusion and three pancreatic function tests were compared in these animals and saline controls. The coefficient of fat absorption on a 5 or 45% fat diet and bentiromide testing could not differentiate animals with or without PI, but fecal chymotrypsin levels were excellent discriminators. All animals with PI had fecal chymotrypsin levels below 67 U/g feces whereas all saline controls were above this level. We conclude that, in this model of PI, the fecal chymotrypsin concentration is the best non-invasive test to determine pancreatic insufficiency.