Cassagno Nadège, Palos-Pinto Antonio, Costet Pierre, Breilh Dominique, Darmon Michel, Bérard Annie M
Laboratoire de Biochimie et de Biologie Moléculaire, EA no 3670, Centre Hospitalier Universitaire de Bordeaux, Université Victor Ségalen Bordeaux 2, 146 rue Léo-Saignat, 33076 Bordeaux, France.
Br J Nutr. 2005 Sep;94(3):346-52. doi: 10.1079/bjn20051512.
Trans fatty acids are found mainly in processed foods. It has been shown that when their intake is high, total cholesterol, LDL-cholesterol and triacylglycerols are elevated, while HDL-cholesterol decreases. To evaluate a possible effect of these compounds, even in low amounts, C57Bl/6J mice were fed for 7 weeks a diet containing 13.6 % energy as partially hydrogenated rapeseed oil-enriched diet (Trans diet). The Trans diet contained 3 % energy as trans 18:1 fatty acid (elaidic acid). Control mice were on an isologous diet containing native rapeseed oil (Rapeseed diet) in which trans fatty acids were undetectable. Total, free and HDL-cholesterol as well as reverse cholesterol transport did not change. However, plasma triacylglycerol and VLDL levels increased. Hepatic gene expression in the Trans v. Rapeseed diet were compared using quantitative RT-PCR. The Trans diet produced a 2-3-fold elevation in mRNA of fatty acid synthase and microsomal transfer protein mRNA, explaining (at least in part) the observed increase in triacylglycerols and VLDL. In addition, mice on the Trans diet developed a deficiency in plasma vitamin E accompanied by a higher concentration of F2-isoprostanes, indicative of increased oxidative stress. The 78 kDa glucose-related protein (GRP78) mRNA expression increased 3-4-fold in liver, suggesting that a response against apoptosis was provoked by lipid peroxidation.
反式脂肪酸主要存在于加工食品中。研究表明，当反式脂肪酸摄入量较高时，总胆固醇、低密度脂蛋白胆固醇和三酰甘油水平会升高，而高密度脂蛋白胆固醇水平会降低。为了评估这些化合物即使在少量摄入时可能产生的影响，将C57Bl/6J小鼠喂食含13.6%能量的部分氢化菜籽油强化饮食（反式饮食）7周。反式饮食中反式18:1脂肪酸（反油酸）提供3%的能量。对照小鼠喂食含天然菜籽油的同源饮食（菜籽油饮食），其中检测不到反式脂肪酸。总胆固醇、游离胆固醇和高密度脂蛋白胆固醇以及胆固醇逆向转运均未改变。然而，血浆三酰甘油和极低密度脂蛋白水平升高。使用定量逆转录聚合酶链反应比较反式饮食组和菜籽油饮食组小鼠的肝脏基因表达。反式饮食使脂肪酸合酶和微粒体转移蛋白mRNA的表达升高了2 - 3倍，这至少部分解释了观察到的三酰甘油和极低密度脂蛋白增加的现象。此外，喂食反式饮食的小鼠出现血浆维生素E缺乏，同时F2 - 异前列腺素浓度升高，这表明氧化应激增加。肝脏中78 kDa葡萄糖相关蛋白（GRP78）mRNA表达增加了3 - 4倍，这表明脂质过氧化引发了针对细胞凋亡的反应。
