AJP - Gastrointestinal and Liver Physiology, Vol 258, Issue 1 38-G44, Copyright © 1990 by American Physiological Society
Effect of diet on triolein absorption in weanling rats
C. A. Flores, P. M. Brannon, M. A. Wells, M. Morrill and O. Koldovsky
Department of Pediatrics, University of Arizona College of Medicine, Tucson 85724.
To determine the effect of altered dietary fat intake on the rate of fat
absorption in the intact animal, we fed male weanling rats either a high
fat-low carbohydrate (HF-LC) (calories: 67% fat, 10% carbohydrate, 20%
protein) or low fat-high carbohydrate (LF-HC) (calories: 10% fat, 67%
carbohydrate, 20% protein) diet for 8 days. Absorption of [14C]triolein was
estimated by determining 1) 14CO2 expiration in breath, 2) intestinal
triglyceride output using Triton WR-1339, an inhibitor of lipoprotein
lipase, and 3) quantitating the disappearance of labeled triolein from the
gastrointestinal tract. Changes in the activity of pancreatic lipase and
amylase confirmed the adaptation to altered fat and carbohydrate intake.
Animals fed the HF-LC diet exhibited approximately twofold greater triolein
disappearance, oxidation, and intestinal triglyceride output compared with
animals fed LF-HC. There was also a highly significant linear relationship
between 14CO2 excretion and intestinal triglyceride output in both diet
groups. These data show that high dietary fat content markedly enhances in
vivo fat absorption in the weanling rat.
