AJP - Gastrointestinal and Liver Physiology, Vol 244, Issue 2 125-G130, Copyright © 1983 by American Physiological Society
Effect of separate feeding of proteins and lipids on pancreatic adaptation in the rat
G. Bourdel
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.
