Morgan J, Leake D S
Department of Biochemistry and Physiology, University of Reading, Whiteknights, Berks, UK.
FEBS Lett. 1993 Nov 1;333(3):275-9. doi: 10.1016/0014-5793(93)80669-l.
We have investigated the effect of pH on LDL oxidation by macrophages (in the presence of iron ions), using a modification of Hanks' balanced salt solution. Increasing the acidity of the medium greatly increased the oxidation of the LDL by the macrophages as measured by thiobarbituric acid-reactive substances or increased uptake and degradation by a second set of macrophages. The rate of oxidation of LDL by iron ions alone, measured in terms of conjugated dienes, was also increased greatly even at mildly acidic pH. It is quite possible that atherosclerotic lesions have an acidic extracellular pH, particularly in the vicinity of macrophages, and the observation that LDL oxidation by macrophages is increased at acidic pH may therefore help to explain why atherosclerotic lesions are apparently one of the very few sites in the body where LDL oxidation occurs.
我们使用改良的汉克斯平衡盐溶液，研究了pH值对巨噬细胞（在铁离子存在下）氧化低密度脂蛋白（LDL）的影响。通过硫代巴比妥酸反应性物质测定，或通过另一组巨噬细胞增加摄取和降解来衡量，提高培养基的酸度会极大地增加巨噬细胞对LDL的氧化。即使在轻度酸性pH条件下，仅铁离子对LDL的氧化速率（以共轭二烯衡量）也会大幅增加。动脉粥样硬化病变的细胞外pH值很可能呈酸性，尤其是在巨噬细胞附近，因此在酸性pH条件下巨噬细胞对LDL的氧化增加这一观察结果，可能有助于解释为什么动脉粥样硬化病变显然是体内极少数发生LDL氧化的部位之一。
