Phosphate uptake by a kidney cell line (LLC-PK1).
Phosphate uptake by a kidney cell line (LLC-PK1).
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肾细胞系（LLC-PK1）对磷酸盐的吸收。
DOI：
10.1152/ajprenal.1983.245.1.f22
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Rabito,CA
中科院分区：
文献类型：
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作者：
Rabito,CA
在肾源性上皮细胞系中研究了无机磷酸盐的吸收。磷酸盐是通过具有载体介导过程的几个特征的机制积累的。流入是由饱和 Na+ 依赖过程和非饱和 Na+ 独立过程引起的。 pH 6.6 和 7.4 下的动力学分析表明，磷酸盐的二元形式是由可饱和 Na+ 依赖性系统转运的形式。培养介质中 Na+ 的存在增加了 Vmax，但不影响 Km。砷酸盐竞争性抑制 Na+ 依赖性磷酸盐转运，在 140 mM Na+ 和 pH 7.4 下，Ki 为 1.2 mM。其他已知的近曲小管磷酸盐重吸收抑制剂也抑制该细胞系的磷酸盐转运。单层任一侧的摄取研究表明，该转运系统优先位于培养的肾细胞的顶膜中。这些结果表明 LLC-PK1 细胞中 Na+ 依赖性磷酸盐转运系统与近端肾小管细胞顶膜中存在的系统非常相似。
The uptake of inorganic phosphate was studied in an epithelial cell line of renal origin. Phosphate was accumulated through a mechanism with several features of a carrier-mediated process. The influx was accounted for by a saturable Na+-dependent and a nonsaturable Na+-independent process. Kinetic analysis at pH 6.6 and 7.4 suggests that the dibasic form of phosphate is the form transported by the saturable Na+-dependent system. The presence of Na+ in the incubation medium increased Vmax without affecting Km. Arsenate competitively inhibited the Na+-dependent phosphate transport with a Ki of 1.2 mM at 140 mM Na+ and pH 7.4. Other known inhibitors of phosphate reabsorption in the proximal tubule also inhibited phosphate transport by this cell line. Uptake studies from either side of the monolayers indicated that this transport system is preferentially located in the apical membrane of the cultured renal cells. These results show a close similarity between the Na+-dependent phosphate transport system in LLC-PK1 cells and the system present in the apical membrane of the proximal tubular cells.