丙二醛和Cu^（2＋）对低密度脂蛋白修饰的比较研究

Modification of Low Density Lipoprotein by Malondialdehyde and Cu￣(2+)

实验比较了丙二醛修饰的低密度脂蛋白（ＭＤＡ－ＬＤＬ）和氧化修饰的低密度脂蛋白（ｏ－ＬＤＬ）的某些理化性质；用放射性受体分析法，从标记配体的可饱和性、可逆性、高亲和力和立体选择性等几方面，证实在小鼠腹腔巨噬细胞（ＭＰＭ）表面存在有特异的ＭＤＡ－ＬＤＬ受体，获得了一系列能反应受体特征的参数；同时，还将ＭＤＡ－ＬＤＬ受体的特征和ｏ－ＬＤＬ的受体特征进行了比较。这些结果将有助于进一步研究ＭＰＭ清道夫受体的多态性及其与动脉粥样硬化的发病原理和防治的关系。

After comparing its fluorescence emission spectrum with that of oxidatively modified low density lipoprotein's (o-LDL's), the malondialdehyde modified LDL' s (MDA-LDL's) receptor on mice peritoneal macrophages(MPM) was identified and was also compared with that of oLDL's by means of radioligand binding assay. The results presented in this paper demonstrated the existence of high affinity binding sites for MDA-LDL as well as o-LDL on MPM. The speciality of the binding was verified by the saturability, reversibility, low K_D value (6.91 and 4. 11 nmol/L for MDA-LDL and o-LDL respectively) and stereoselectivity. The other parameters such as nH、t1/2 were also determined. These findings may afford us useful theoretic foundation in the study of scavenger receptor multiplicity and its relationship to the genesis. protection and treatment of artherosclerosis.