Response of rat exocrine pancreas to high-fat and high-carbohydrate diets

Intake of diets with high fat content is a risk factor for acute pancreatit is and pancreatic cancer. The underlying mechanisms leading to the developm ent of these diseases due to high fat intake are currently unknown. The cur rent study was designed in rats to determine the physiologic and pathologic al consequences of a high-fat diet that contained excess amounts of cottons eed oil or a high-carbohydrate diet that contained high amounts of sucrose on the exocrine pancreas. Rats were maintained on the diets for 4 weeks, an d a cannula was inserted into the right jugular vein and one into the pancr eatic duct for collection of pancreatic juice. Volume of the pancreatic jui ce and concentrations of amylase, lipase, and trypsinogen in the pancreatic juice were measured before and after infusions of CCK-8, Results showed th at basal and CCK-stimulated pancreatic outputs of volume, amylase and lipas e but not trypsinogen, were significantly elevated in intact rats given a h igh-fat diet when compared with rats given a high-carbohydrate diet. Forty- eight hours later, rats were sacrificed, and parts of the pancreas were rem oved for isolation of pancreatic acinar cells and for histopathologic studi es, Pancreatic acini isolated from rats on a high-fat diet showed significa ntly lower basal and CCK-stimulated amylase release when compared with thos e on a high-carbohydrate diet, Histology of the pancreas of rats on a high- carbohydrate diet appeared normal; however, the pancreas of rats on high-fa t diet showed significant alterations in exocrine pancreas. These results s howed abnormalities in the exocrine pancreas of rats on a high-fat diet, th at were not found in rats on a high-carbohydrate diet; further, they suppor t the contention that a high-fat diet has a deleterious effect on the pancr eas.