摘要

Alcoholic fatty liver results from an impaired fatty acid catabolism due to blockade of PPAR alpha and increased lipogenesis due to activation of sterol regulatory element-binding protein (SREBP)-lc. Because both oxidized fats (OF) and conjugated linoleic acids (CLA) have been demonstrated in rats to activate hepatic PPARa, we tested the hypothesis that these fats are able to prevent ethanol-induced triacylglycerol accumulation in the liver by upregulation of PPAR alpha-responsive genes. Forty-eight male rats were assigned to 6 groups and fed isocaloric liquid diets containing either sunflower oil (SFO) as a control fat, OF prepared by heating of SFO, or CLA, in the presence and absence of ethanol, for 4 wk. Administration of ethanol lowered mRNA concentrations of PPAR alpha and the PPAR alpha-responsive genes medium chain acylCoA dehydrogenase, long chain acyl-CoA dehydrogenase, acyl-CoA oxicase, carnitine palmitoyl-CoA transferase 1, and cytochrome P450 4AI and increased triacylglycerol concentrations in the liver (P < 0.05). Of increased hepatic mRNA concentrations of PIPAR alpha-responsive genes and lowered hepatic triacylglycerol concentrations compared with SFO (P < 0.05) whereas CLA did not. Rats fed OF with ethanol had similar mRNA concentrations of PPAR alpha-responsive genes and similar triacylglycerol concentrations in the liver as rats fed SFO or CLA without ethanol. In contrast, hepatic mRNA concentrations of SREBP-1c and fatty acid synthase were not altered by OF or CLA compared with SFO. This study shows that OF prevents an alcohol-induced triacylglycerol accumulation in rats possibly by upregulation of hepatic PPAR alpha responsive genes involved in oxidation of fatty acids, whereas CLA does not exert such an effect. J. Nutr. 137: 77-83, 2007.

  • 出版日期2007-1