Girard Aurélie, Madani Sihem, El Boustani Es Saddik, Belleville Jacques, Prost Josiane
Université de Bourgogne, UPRES Lipides Nutrition EA 2422, Faculté des Sciences Gabriel, Dijon, France.
Nutrition. 2005 Feb;21(2):240-8. doi: 10.1016/j.nut.2004.04.022.
Larger doses of fructose and saturated fat have been associated with oxidative stress and development of hypertension. The effects of modest amounts of fructose and saturated fatty acids on oxidative stress are unknown.
To increase knowledge on this question, 10-wk-old spontaneously hypertensive rats and Wistar rats were fed for 8 wk with a control diet or an experimental diet enriched with fructose (18%) and saturated fatty acids (11%; FS diet). The total antioxidant status of organs and red blood cells was assayed by monitoring the rate of free radical-induced red blood cell hemolysis. Sensitivity of very low-density lipoprotein and low-density lipoprotein (VLDL-LDL) to copper-induced lipid peroxidation was determined as the production of thiobarbituric acid-reactive substances. Antioxidant enzymes and vitamins were also measured to establish the oxidative stress effect.
The FS diet did not affect blood pressure in either strain, but it increased plasma insulin concentrations only in Wistar rats without affecting those of glucose of either strain. The FS diet significantly enhanced plasma and VLDL-LDL triacylglycerol concentrations without affecting concentrations of VLDL-LDL thiobarbituric acid-reactive substances. The decreased content of arachidonic acid and total polyunsaturated fatty acids in VLDL-LDL by the FS diet may have prevented lipid peroxidation in this fraction. Moreover, FS consumption by both strains was accompanied by a significant increase in total antioxidant capacity of adipose tissue, muscle, heart, and liver. This may have resulted from increased tissue ascorbic acid levels and glutathione peroxidase and glutathione reductase activities in tissues.
These findings clearly indicate that the FS diet did not alter blood pressure of spontaneously hypertensive rats and Wistar rats. The FS diet resulted in hypertriglyceridemia but increased the total antioxidant status, which may prevent lipid peroxidation in these rats.
大量的果糖和饱和脂肪与氧化应激及高血压的发展有关。适量的果糖和饱和脂肪酸对氧化应激的影响尚不清楚。
为了增加对这个问题的了解，给10周龄的自发性高血压大鼠和Wistar大鼠喂食对照饮食或富含果糖（18%）和饱和脂肪酸（11%；FS饮食）的实验饮食8周。通过监测自由基诱导的红细胞溶血速率来测定器官和红细胞的总抗氧化状态。测定极低密度脂蛋白和低密度脂蛋白（VLDL-LDL）对铜诱导的脂质过氧化的敏感性，以硫代巴比妥酸反应性物质的产生来衡量。还测量了抗氧化酶和维生素以确定氧化应激效应。
FS饮食对两种品系的血压均无影响，但仅在Wistar大鼠中增加了血浆胰岛素浓度，而对两种品系的血糖均无影响。FS饮食显著提高了血浆和VLDL-LDL三酰甘油浓度，但不影响VLDL-LDL硫代巴比妥酸反应性物质的浓度。FS饮食使VLDL-LDL中花生四烯酸和总多不饱和脂肪酸含量降低，可能阻止了该部分的脂质过氧化。此外，两种品系摄入FS后，脂肪组织、肌肉、心脏和肝脏的总抗氧化能力均显著增加。这可能是由于组织中抗坏血酸水平升高以及组织中谷胱甘肽过氧化物酶和谷胱甘肽还原酶活性增加所致。
这些发现清楚地表明，FS饮食不会改变自发性高血压大鼠和Wistar大鼠的血压。FS饮食导致高甘油三酯血症，但增加了总抗氧化状态，这可能预防这些大鼠的脂质过氧化。
