The trans-10,cis-12 isomer of conjugated linoleic acid reduces hepatic triacylglycerol content without affecting lipogenic enzymes in hamsters.
Conjugated linoleic acid (CLA) refers to the positional and geometric dienoic isomers of linoleic acid. The dietary intake of CLA has been associated with changes in lipid metabolism. The aim of the present work was to assess the effects of the two main isomers of CLA on sterol regulatory element binding protein (SREBP)-1a and SREBP-1c mRNA levels, as well as on mRNA levels and the activities of several lipogenic enzymes in liver. For this purpose hamsters were fed an atherogenic diet supplemented with 5 g linoleic acid, cis-9,trans-11 or trans-10,cis-12 CLA/kg diet for 6 weeks. The trans-10,cis-12 isomer intake produced significantly greater liver weight, but also significantly decreased liver fat accumulation. No changes in mRNA levels of SREBP-1a, SREBP-1c and lipogenic enzymes, or in the activities of these enzymes, were observed. There was no effect of feeding cis-9,trans-11 CLA. These results suggest that increased fat accumulation in liver does not occur on the basis of liver enlargement produced by feeding the trans-10,cis-12 isomer of CLA in hamsters. The reduction in hepatic triacylglycerol content induced by this isomer was not attributable to changes in lipogenesis.
Zabala
Amaia
A
Department of Nutrition and Food Science, University of País Vasco, Paseo de la Universidad 7, 01006 Vitoria, Spain.
Churruca
Itziar
I
Macarulla
M Teresa
MT
Rodríguez
Víctor M
VM
Fernández-Quintela
Alfredo
A
Martínez
J Alfredo
JA
Portillo
María P
MP
D000103:Acetyl-CoA Carboxylase / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D006224:Cricetinae; D004268:DNA-Binding Proteins / Q000378:metabolism; D004032:Diet; D064429:Fatty Acid Synthases / Q000378:metabolism; D007328:Insulin / Q000097:blood; D007536:Isomerism; D044243:Linoleic Acids, Conjugated / Q000008:administration & dosage / Q000494:pharmacology*; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism*; D008297:Male; D008647:Mesocricetus; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism*
D001786:Blood Glucose; D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D007328:Insulin; D044243:Linoleic Acids, Conjugated; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; D014280:Triglycerides; D064429:Fatty Acid Synthases; D000103:Acetyl-CoA Carboxylase