Stulnig T M, Jürgens G, Chen Q, Moll D, Schönitzer D, Jarosch E, Wick G
Institute for General and Experimental Pathology, University of Innsbruck, Austria.
Atherosclerosis. 1996 Sep 27;126(1):85-94. doi: 10.1016/0021-9150(96)05896-0.
Atherosclerosis is a common problem among the elderly. Because lipid peroxidation is considered a contributor to the development of atherosclerosis, we compared oxidative properties of lipoproteins in an otherwise healthy (SENIEUR-classified) aged population (65-74 years) with young controls (18-30 years). Relative amounts of oxidatively altered low density lipoprotein (LDL), estimated by means of an antibody against LDL modified by 4-hydroxynonenal, a product of lipid peroxidation, were increased marginally in serum from the elderly (9.8 vs. 7.4%, P = 0.07). In contrast, isolated LDL from the elderly revealed a decreased susceptibility to in vitro oxidation: the lag time was increased (2.34 vs. 2.10 h, P < 0.01), and the maximal rate of LDL oxidation decreased (0.88 vs. 1.01 O.D./h, P = 0.001). However, there were no age-related changes in lipid composition of native LDL and consumption of fatty acids during in vitro oxidation. The serum concentrations of ascorbic acid and most lipophilic anti-oxidants (the latter expressed per g serum lipids) were significantly decreased in the elderly except tocopherols which tended to be higher. In conclusion, our data reveal paradox age-related alterations of LDL as to its behaviour in oxidation in vivo vs. in vitro.
动脉粥样硬化是老年人中的常见问题。由于脂质过氧化被认为是动脉粥样硬化发展的一个促成因素，我们比较了健康（根据SENIEUR标准分类）老年人群（65 - 74岁）与年轻对照组（18 - 30岁）中脂蛋白的氧化特性。通过一种针对由脂质过氧化产物4 - 羟基壬烯醛修饰的低密度脂蛋白（LDL）的抗体来估计氧化改变的LDL的相对含量，在老年人血清中略有增加（9.8%对7.4%，P = 0.07）。相比之下，从老年人中分离出的LDL显示出对体外氧化的敏感性降低：延滞时间增加（2.34小时对2.10小时，P < 0.01），并且LDL氧化的最大速率降低（0.88吸光度/小时对1.01吸光度/小时，P = 0.001）。然而，天然LDL的脂质组成以及体外氧化过程中脂肪酸的消耗没有与年龄相关的变化。除了生育酚含量有升高趋势外，老年人血清中抗坏血酸和大多数亲脂性抗氧化剂的浓度（后者以每克血清脂质表示）显著降低。总之，我们的数据揭示了LDL在体内与体外氧化行为方面与年龄相关的矛盾变化。
