Dzeletovic S, Babiker A, Lund E, Diczfalusy U
Department of Medical Laboratory Sciences and Technology, Karolinska Institute, Sweden.
Chem Phys Lipids. 1995 Nov 17;78(2):119-28. doi: 10.1016/0009-3084(95)02489-6.
Cholesterol oxidation products (oxysterols) have been implicated in several aspects of atherogenesis; they affect key enzymes in cholesterol homeostasis, induce calcification in vascular cells and possess cytotoxic properties. Oxysterols are formed during oxidative modification of low density lipoprotein (LDL). Using a recently developed method based on isotope dilution-mass spectrometry, the kinetics of formation of oxysterols during oxidation of LDL by cupric ions or soybean lipoxygenase was studied. The same products, mainly 7- and 5-oxygenated cholesterol, were formed by the two oxidation methods. Virtually no side-chain oxidized oxysterols were formed. During the oxidations, preferentially esterified cholesterol was consumed and consumption of polyunsaturated fatty acids and formation of conjugated dienes preceded the appearance of oxysterols. Cholesterol 7-hydroperoxides potential cytotoxins, were present in LDL oxidized by copper or lipoxygenase.
胆固醇氧化产物（氧化甾醇）与动脉粥样硬化形成的多个方面有关；它们影响胆固醇稳态中的关键酶，诱导血管细胞钙化并具有细胞毒性。氧化甾醇在低密度脂蛋白（LDL）的氧化修饰过程中形成。使用最近开发的基于同位素稀释-质谱法的方法，研究了铜离子或大豆脂氧合酶氧化LDL过程中氧化甾醇的形成动力学。两种氧化方法形成了相同的产物，主要是7-和5-氧化胆固醇。几乎没有形成侧链氧化的氧化甾醇。在氧化过程中，优先消耗酯化胆固醇，多不饱和脂肪酸的消耗和共轭二烯的形成先于氧化甾醇的出现。胆固醇7-氢过氧化物（潜在的细胞毒素）存在于被铜或脂氧合酶氧化的LDL中。
