Effects of dietary conjugated linoleic acid at high-fat levels on triacylglycerol regulation in mice.
OBJECTIVE
Our aim was to investigate the effects of dietary conjugated linoleic acid (CLA) at high-fat (HF) levels on parameters related to triacylglycerol (TG) regulation and some potential impacts on liver damage.


METHODS
Growing mice were fed a control diet (7% corn oil), an HF diet containing 20% corn oil, or an HF diet containing 3% CLA (HF + CLA) for 30 d. Tissue and organ weights, plasma and tissue TG levels, and parameters related to their regulation were evaluated. Liver oxidative status was also assessed.


RESULTS
Dietary CLA showed detrimental and beneficial effects. CLA added to the HF diet caused hepatomegaly (+32%) and exacerbated the hepatic TG accumulation (+168%) observed with the HF diet without inducing liver damage; however, it significantly reduced plasma TG concentrations (-37%) and normalized muscular TG content. An increase in glutathione was associated with total normalization of liver lipid peroxidation. In addition, HF + CLA caused dystrophy of epididymal fat pads, even when the HF diet had increased the adipose tissue mass (30%). The biochemical mechanisms involved in the regulation of lipid levels were related to reduced (-20%) hepatic very low-density lipoprotein-TG secretion and decreased muscle (-35%) and adipose (-49%) tissue contributions to the removal of plasma TG by lipoprotein lipase enzymes.


CONCLUSIONS
Examination of CLA at HF levels showed hepatomegaly and exacerbation of lipid accretion as a negative impact; however, some positive aspects such as hypotriglyceridemia and protection against oxidative stress were also induced. Even the fat reduction is nutritionally important for weight control; the biochemical mechanisms whereby CLA mediates the potential effects could produce undesirable metabolic alterations.
Andreoli
María F
MF
Departamento de Ciencias Biológicas, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Santa Fe, Argentina.
Gonzalez
Marcela A
MA
Martinelli
Marcela I
MI
Mocchiutti
Norberto O
NO
Bernal
Claudio A
CA
D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002784:Cholesterol / Q000097:blood; D003314:Corn Oil / Q000494:pharmacology; D004041:Dietary Fats / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004822:Epididymis; D005978:Glutathione / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects*; D015227:Lipid Peroxidation; D008071:Lipoprotein Lipase / Q000378:metabolism; D008099:Liver / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D051379:Mice; D009929:Organ Size; D018384:Oxidative Stress; D014280:Triglycerides / Q000378:metabolism*
D004041:Dietary Fats; D044243:Linoleic Acids, Conjugated; D014280:Triglycerides; D003314:Corn Oil; D002784:Cholesterol; D008071:Lipoprotein Lipase; D005978:Glutathione