Knipping G, Rotheneder M, Striegl G, Esterbauer H
Institute of Medical Biochemistry, University of Graz, Austria.
J Lipid Res. 1990 Nov;31(11):1965-72.
The objective of this study was to determine the level of antioxidants, the content of fatty acids and peroxidation products, and the resistance against oxidation of native porcine LDL1 and LDL2. There were no significant differences in the fatty acid distribution of both native low density lipoprotein (LDL) subfractions, which was similar to that of human LDL. The total amount of alpha- and gamma-tocopherol of pig LDL was significantly lower than in human LDL, and beta-carotene, lycopene, and retinyl esters were totally absent. Levels of thiobarbituric acid-reacting substances (TBARS) and lipid peroxides in freshly isolated pig LDL subfractions were below or only slightly above the detection limit. The susceptibility to oxidation of both LDL subfractions was investigated by addition of Cu2+ as prooxidant. The results show that pig LDL subfractions are much more susceptible to oxidation as measured by the duration of the lag phase preceding the onset of rapid lipid peroxidation. From the low content of vitamin E one would expect even much shorter lag phases. The possibility therefore exists that pig LDL contains additional, and as yet unidentified, antioxidants.
本研究的目的是确定天然猪低密度脂蛋白1（LDL1）和低密度脂蛋白2（LDL2）的抗氧化剂水平、脂肪酸和过氧化产物含量以及抗氧化能力。两种天然低密度脂蛋白（LDL）亚组分的脂肪酸分布没有显著差异，这与人类LDL相似。猪LDL中α-生育酚和γ-生育酚的总量显著低于人类LDL，且完全不存在β-胡萝卜素、番茄红素和视黄酯。新鲜分离的猪LDL亚组分中硫代巴比妥酸反应物质（TBARS）和脂质过氧化物的水平低于或仅略高于检测限。通过添加Cu2+作为促氧化剂来研究两种LDL亚组分的氧化敏感性。结果表明，以快速脂质过氧化开始前的滞后期持续时间衡量，猪LDL亚组分对氧化更敏感。鉴于维生素E含量低，人们预期滞后期会更短。因此，猪LDL可能含有其他尚未确定的抗氧化剂。
