Dietary effects on pancreatic exocrine function. Experiments on the isolated perfused rat pancreas

Studies of the response of the isolated perfused rat pancreas to three doses of secretin (5.0, 10.0, 18.75 U/h) and CCK (0.6, 1.5, 2.4 U/h) show that a 35-day administration of a carbohydrate-rich (60% carbohydrate, 3% fat, 20% protein) or fat-rich (34% fat, 11.3% carbohydrate, 29.8% protein) diet increases the sensitivity of the gland to these hormones compared to a standard diet (50.5% carbohydrate, 4% fat, 19% protein). The maximal secretory flow on stimulation by secretin and on a combined stimulation by secretin (2.5 U/h) plus CCK (1.8 U/h) is significantly (p less than 0.05 and p less than 0.01, respectively) lower in both experimental diets than in controls, whereas the maximal protein and enzyme secretion is diminished only in the secretin plus CCK-stimulated pancreas of rats fed a fat-rich diet. A carbohydrate-rich diet results in a relative increase in amylase secretion and decrease in lipase and chymotrypsinogen output. Compared to controls, the fat-rich diet leads to a stronger secretion of lipase and chymotrypsinogen and to a reduced amylase secretion. This adaptation of the exocrine pancreatic function is rather due to changes in the organ itself than to an altered hormonal stimulation.