MCA Research Laboratory, Department of Physiology, University of Turku, Turku, Finland.
Ann Med. 2010 Oct;42(7):521-9. doi: 10.3109/07853890.2010.510932.
Serum lipoproteins, the carriers of cholesterol and other lipophilic substances in blood, are known to contain variable amounts of lipid peroxides. We investigated the transport of food-derived and endogenously formed lipid peroxides by serum lipoproteins under physiological conditions.
Five independent trials were conducted in which different groups of healthy volunteers either consumed a test meal (a standard hamburger meal rich in lipid peroxides) or underwent strenuous physical exercise. The transport function was characterized by analyzing the kinetics of lipid peroxides in lipoprotein fractions. For evaluation of their potential involvement, indicators of oxidative stress (8-isoprostanes, malondialdehyde, 8-oxo-deoxyguanosine), antioxidant functions (total antioxidant potential, paraoxonase activity), and serum lipids were also analyzed.
We found that food lipid peroxides are incorporated into serum triglyceride-rich lipoproteins and low-density lipoprotein, directing the flow of lipid peroxides towards peripheral tissues. High-density lipoprotein appears to have an opposite and protective function, and is able to respond to oxidative stress by substantially increasing the reverse transport of lipid peroxides.
We propose that the specific atherosclerosis-related effects of serum lipoproteins are not explained by cholesterol transport alone and may rather result from the transport of the more directly atherogenic lipid peroxides.
血清脂蛋白是血液中胆固醇和其他脂溶性物质的载体，已知其含有不同量的脂质过氧化物。我们在生理条件下研究了血清脂蛋白对食物来源和内源性形成的脂质过氧化物的转运。
进行了五次独立试验，其中不同组的健康志愿者要么食用测试餐（富含脂质过氧化物的标准汉堡餐），要么进行剧烈的体育锻炼。通过分析脂蛋白馏分中脂质过氧化物的动力学来描述转运功能。为了评估其潜在的参与，还分析了氧化应激的指标（8-异前列腺素、丙二醛、8-氧-脱氧鸟苷）、抗氧化功能（总抗氧化能力、对氧磷酶活性）和血清脂质。
我们发现食物脂质过氧化物被掺入血清甘油三酯丰富的脂蛋白和低密度脂蛋白中，将脂质过氧化物引导至外周组织。高密度脂蛋白似乎具有相反的保护功能，并能够通过显著增加脂质过氧化物的反向转运来应对氧化应激。
我们提出，血清脂蛋白与动脉粥样硬化相关的特定作用不能仅通过胆固醇转运来解释，而可能是由于更直接致动脉粥样硬化的脂质过氧化物的转运所致。
