论文部分内容阅读
用未标记氧化修饰极低密度脂蛋白（ｏｘ－ＶＬＤＬ）、ｎ－ＶＬＤＬ、乙酰ＬＤＬ竞争１２５Ｉ－ｏｘ－ＶＬＤＬ与巨噬细胞的结合。在浓度为２００μｇ蛋白／ｍｌ时，分别抑制标记ｏｘ－ＶＬＤＬ结合量的７０～７８％、６０～７０％和２５～３５％。用未标记ｏｘ－ＶＬＤＬ竟争１２５Ｉ－ｎ－ＶＬＤＬ与巨噬细胞的结合，能抑制７７％。结果说明ｏｘ－ＶＬＤＬ主要通过ｎ－ＶＬＤＬ受体进入巨噬细胞。以ｏｘ－ＶＬＤＬ与ｏｘ－ＬＤＬ进行交叉竞争时，ｏｘ－ＶＬＤＬ与ｏｘ－ＬＤＬ自身可抑制标记ｏｘ－ＶＬＤＬ或ｏｘ－ＬＤＬ的７５～８２％，而ｏｘ－ＶＬＤＬ或ｏｘ－ＬＤＬ的交叉竞争仅３８～４０％。表明ｏｘ－ＶＬＤＬ与ｏｘ－ＬＤＬ有部分共同的构象与巨噬细胞的脂蛋白受体结合，但ｏｘ－ＶＬＤＬ不是经ｏｘ－ＬＤＬ受体被巨噬细胞摄取。
Unlabeled oxidatively modified very low density lipoprotein (ox-VLDL), n-VLDL, acetyl LDL competed for the binding of 125I-ox-VLDL to macrophages. At concentrations of 200 μg protein / ml, 70 to 78%, 60 to 70% and 25 to 35% of labeled ox-VLDL binding were inhibited, respectively. Competition for 125I-n-VLDL with macrophages competed with unlabeled ox-VLDL for 77% inhibition. The results indicate that ox-VLDL mainly enters macrophages via n-VLDL receptors. Ox-VLDL and ox-LDL themselves inhibit 75-82% of labeled ox-VLDL or ox-LDL when ox-VLDL and ox-LDL cross-compete, while the cross-competition of ox-VLDL or ox-LDL is only 38 ~ 40%. This suggests that the partially conformational relationship between ox-VLDL and ox-LDL binds to macrophage lipoprotein receptors, but ox-VLDL is not taken up by macrophages via ox-LDL receptors.