Effect of separate feeding of proteins and lipids on pancreatic adaptation in the rat.
In agreement with what is known of pancreatic adaptation to dietary composition, a progressive lowering of amylase-to-chymotrypsinogen ratio was observed in the pancreases of rats fed mixed diets of increasing casein and decreasing carbohydrate contents. The same changes in ratio were found when casein alone was increased in otherwise isonitrogenous meals fed to rats provided ad libitum with a protein-free diet. Pancreatic accumulation of chymotrypsinogen was increased while that of amylase was decreased in spite of low-protein and high-carbohydrate intakes. Lowering the lipid content of the protein-free diet reduced the effectiveness of casein meals in lowering the amylase-to-chymotrypsinogen ratio. It is concluded that 1) the capacity of protein-rich diets to induce adaptative changes in pancreatic secretion does not depend on the absolute amount of proteins passing through the duodenum but rather on the increased protein concentration in the alimentary bolus, 2) protein concentration affects both amylase and chymotrypsinogen, and 3) lipids have a cooperative effect.
D000681:Amylases / Q000378:metabolism*; D000818:Animals; D002364:Caseins / Q000494:pharmacology; D002919:Chymotrypsinogen / Q000378:metabolism*; D004041:Dietary Fats / Q000494:pharmacology*; D004044:Dietary Proteins / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D010179:Pancreas / Q000187:drug effects / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains
D002364:Caseins; D004041:Dietary Fats; D004044:Dietary Proteins; D002919:Chymotrypsinogen; D000681:Amylases