The application of rapid kinetic techniques to the transport of thymidine and 3‐O‐methylglucose into mammalian cells in suspension culture
The application of rapid kinetic techniques to the transport of thymidine and 3‐O‐methylglucose into mammalian cells in suspension culture
复制标题
快速动力学技术在悬浮培养中将胸苷和 3-O-甲基葡萄糖转运至哺乳动物细胞中的应用
DOI：
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发表时间：
1976
影响因子：
5.6
通讯作者：
P. Plagemann
中科院分区：
文献类型：
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作者：
R. Wohlhueter;R. Marz;J. Graff;P. Plagemann
描述了以1.5秒的间隔测量悬浮液中营养物质向哺乳动物细胞的运输的技术。通过这些技术的应用，证明在缺乏μ的Novikoff大鼠肝癌细胞中存在一个可饱和的(Km=85 ATPM)非浓缩的胸腺嘧啶核苷转运系统。当胸腺嘧啶核苷浓度低于Km时，该系统的运行速度足以在8秒内几乎完全平衡细胞内和细胞外胸腺苷池。在磷酸化细胞中，运输系统以类似的速度运行，因此细胞内的磷酸化对胸腺嘧啶核苷掺入核苷酸是限速的。摄取3-O-甲基葡萄糖的速度相当，在25秒内达到内外池之间90%的平衡。通过简单扩散摄取胞嘧啶的速度要慢100倍。
Techniques are described by which the transport of nutrients into mammalian cells in suspension can be measured at intervals of 1.5 seconds. By application of these techniques, the existence of a saturable (Km = 85 μM), non‐concentrative, transport system for thymidine was demonstrated in Novikoff rat hepatoma cells depleted of ATP. At concentrations of thymidine less than the Km, this system operated at velocities sufficient to nearly completely equilibrate intra‐ and extra‐cellular thymidine pools within 8 seconds. In phosphorylating cells, the transport system operated with similar rapidity, so that intracellular phosphorylation was rate‐limiting for the incorporation of thymidine into nucleotides. Uptake of 3‐O‐methylglucose occurred at comparable velocities, attaining 90% of equilibrium between internal and external pools within 25 seconds. Uptake of cytosine by simple diffusion was 100 times slower.