Uptake and degradation of plasma lipoproteins by human choriocarcinoma cells in culture.
Uptake and degradation of plasma lipoproteins by human choriocarcinoma cells in culture.
复制标题
培养中的人绒毛膜癌细胞对血浆脂蛋白的摄取和降解。
DOI：
10.1210/endo-104-1-8
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发表时间：
1979
期刊：
影响因子：
4.8
通讯作者：
J. C. Porter
中科院分区：
文献类型：
--
作者：
E. Simpson;D. Bilheimer;P. Macdonald;J. C. Porter
以[~(125)I]碘-低密度脂蛋白为底物，研究了培养的人绒毛癌细胞对低密度脂蛋白的摄取和降解。在37℃时，细胞摄取[125I]iodo-LDL迅速，在4.5h内达到稳定状态，滞留约1h后，[125I]iodo-LDL线性降解至少30h，摄取和降解与培养液中[125I]iodo-LDL浓度的关系与高亲和力(表观Kd，4×10-9M)、低容量细胞表面受体结合的结论一致。高密度脂蛋白几乎不引起[125I]碘-低密度脂蛋白从这些受体部位移位。在4℃时，摄取[~(125)I]碘-低密度脂蛋白的程度降低了75%，但其降解被完全抑制。在4℃时，在洗浴细胞的培养液中加入肝素(10 mg/ml)，可使大部分结合的[125I]碘-低密度脂蛋白从细胞中解离；而在37℃时，加入肝素可使[125I]-I-低密度脂蛋白从细胞中解离。
The uptake and degradation of low density lipoprotein (LDL) by human choriocarcinoma cells in culture was studied using [125I]iodo-LDL as the substrate. At 37 C, uptake of [125I]iodo-LDL was rapid, attaining a steady state within 4.5 h. After a lag time of about 1 h, degradation of [125I]iodo-LDL proceeded linearly for at least 30 h. The relationship of uptake and degradation to the concentration of [125I]iodo-LDL in the culture medium was consistent with the conclusion that both of these processes involved binding to a population of high affinity (apparent Kd, 4 × 10-9 M), low capacity cell surface receptors. High density lipoprotein caused little displacement of [125I]iodo- LDL from these receptor sites. At 4 C, the extent of uptake of [125I]iodo-LDL was reduced by 75%, whereas its degradation was completely inhibited. At 4 C, addition of heparin (10 mg/ml) to the culture medium bathing the cells caused dissociation of most of the bound [125I]iodo-LDL from the cells; but at 37 C, addition of heparin cau...