Back to Search
Start Over
Activity and mRNA levels of enzymes involved in hepatic fatty acid synthesis and oxidation in mice fed conjugated linoleic acid.
- Source :
-
Biochimica et biophysica acta [Biochim Biophys Acta] 2003 Apr 08; Vol. 1631 (3), pp. 265-73. - Publication Year :
- 2003
-
Abstract
- The effects of dietary conjugated linoleic acid (CLA) on the activity and mRNA levels of hepatic enzymes involved in fatty acid synthesis and oxidation were examined in mice. In the first experiment, male ICR and C57BL/6J mice were fed diets containing either a 1.5% fatty acid preparation rich in CLA or a preparation rich in linoleic acid. In the second experiment, male ICR mice were fed diets containing either 1.5% linoleic acid, palmitic acid or the CLA preparation. After 21 days, CLA relative to linoleic acid greatly decreased white adipose tissue mass but caused hepatomegaly accompanying an approximate 10-fold increase in the tissue triacylglycerol content irrespective of mouse strain. CLA compared to linoleic acid greatly increased the activity and mRNA levels of various lipogenic enzymes in both experiments. Moreover, CLA increased the mRNA expression of Delta6- and Delta5-desaturases, and sterol regulatory element binding protein-1 (SREBP-1). The mitochondrial and peroxisomal palmitoyl-CoA oxidation rate was about 2.5-fold higher in mice fed CLA than in those fed linoleic acid in both experiments. The increase was associated with the up-regulation of the activity and mRNA expression of various fatty acid oxidation enzymes. The palmitic acid diet compared to the linoleic acid diet was rather ineffective in modulating the hepatic lipid levels or activity and mRNA levels of enzymes in fatty acid metabolism. It is apparent that dietary CLA concomitantly increases the activity and mRNA levels of enzymes involved in fatty acid synthesis and oxidation, and desaturation of polyunsaturated fatty acid in the mouse liver. Both the activation of peroxisomal proliferator alpha and up-regulation of SREBP-1 may be responsible for this.
- Subjects :
- 3-Hydroxyacyl CoA Dehydrogenases analysis
Acetyl-CoA C-Acyltransferase analysis
Animals
Carbon-Carbon Double Bond Isomerases analysis
Delta-5 Fatty Acid Desaturase
Enoyl-CoA Hydratase analysis
Fatty Acid Desaturases analysis
Fatty Acid Desaturases metabolism
Fatty Acids biosynthesis
Linoleic Acid administration & dosage
Linoleoyl-CoA Desaturase
Liver enzymology
Liver growth & development
Mice
Mice, Inbred C57BL
Mice, Inbred ICR
Organ Size
Oxidation-Reduction
RNA, Messenger analysis
Racemases and Epimerases analysis
3-Hydroxyacyl CoA Dehydrogenases metabolism
Acetyl-CoA C-Acyltransferase metabolism
Carbon-Carbon Double Bond Isomerases metabolism
Dietary Fats, Unsaturated pharmacology
Enoyl-CoA Hydratase metabolism
Fatty Acids metabolism
Linoleic Acid pharmacology
Lipids biosynthesis
Liver metabolism
Racemases and Epimerases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0006-3002
- Volume :
- 1631
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Biochimica et biophysica acta
- Publication Type :
- Academic Journal
- Accession number :
- 12668178
- Full Text :
- https://doi.org/10.1016/s1388-1981(03)00038-6