Protein and energy metabolism of young male Wistar rats fed conjugated linoleic acid as structured triacylglycerol.
Twelve 4-week-old male Wistar rats weighing 100 g were fed diets semi-ad libitum for 22 d containing either 1.5% conjugated linoleic acid (CLA-diet) or high oleic sunflower oil (Control-diet). The CLA was structured triacylglycerol with predominantly cis-9, trans-11 and trans-10, cis-12 fatty acid isomers in the inner position and oleic acid in the other positions of the glycerol molecule. The rats were kept individually in metabolic cages. From days 8-16 energy, nitrogen (N) and carbon (C) balances as well as gas exchange measurements in open-air circuit respiration chambers were performed. CLA had no significant influence on feed intake, daily gain in weight or feed conversion efficiency, but the digestibility of nutrients and energy was significantly reduced (except for fat). CLA did not affect N-balance, but reduced the level of daily retained fat (RQ-method: 0.107 vs. 0.417 g/d, p < 0.01) and consequently energy retention in fat. This was explained by increased heat production (HP, RQ-method: 224.6 vs. 214.6 kJ/d, p < 0.001) caused by a higher fat oxidation (28.9% vs. 22.3%, p < 0.001) at the expense of oxidation of carbohydrates (65.6% vs. 71.4%, p < 0.001), while there was no significant effect on the oxidation of protein (5.5% vs. 6.3%). Consequently, the non-protein respiratory quotient (RQnp) was lower in the rats fed the CLA-diet than in the rats fed the Control-diet (0.907 vs. 0.928, p < 0.001). Plasma total lipids of the CLA-fed rats had higher concentrations of the cis-9, trans-11 than the trans-10, cis-12 CLA-isomer. This study shows that young male Wistar rats respond to CLA fed as structured triacylglycerol.
Jørgensen
Henry
H
Department of Animal Health and Bioscience, Faculty of Agricultural Sciences, University of Arhus, Tjele, Denmark. henry.jorgensen@agrsci.dk
Hansen
Christina Hørup
CH
Mu
Huiling
H
Jakobsen
Kirsten
K
D000818:Animals; D004734:Energy Metabolism / Q000187:drug effects*; D044243:Linoleic Acids, Conjugated / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D011506:Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014280:Triglycerides / Q000378:metabolism*
D044243:Linoleic Acids, Conjugated; D011506:Proteins; D014280:Triglycerides