Nucleoside transport in Walker 256 rat carcinosarcoma and S49 mouse lymphoma cells. Differences in sensitivity to nitrobenzylthioinosine and thiol reagents.
Nucleoside transport in Walker 256 rat carcinosarcoma and S49 mouse lymphoma cells. Differences in sensitivity to nitrobenzylthioinosine and thiol reagents.
复制标题
Walker 256 大鼠癌肉瘤和 S49 小鼠淋巴瘤细胞中的核苷转运。
DOI：
10.1042/bj2320681
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Noel,LD
中科院分区：
文献类型：
--
作者：
Belt,JA;Noel,LD
用步行者256大鼠癌肉瘤细胞和S49小鼠淋巴瘤细胞研究了核苷转运特性。在步行者256细胞中，尿苷、胸苷和腺苷摄取的初始速率对核苷转运抑制剂硝基苄硫代肌苷（NBMPR）（1 μ M）不敏感，但被另一种核苷转运抑制剂双嘧达莫（10 μ M）部分抑制。相反，这些核苷在S49细胞中的转运被这两种抑制剂完全阻断。步行者256和S49细胞中的核苷转运对巯基试剂对氯汞苯磺酸盐（pCMBS）的敏感性也不同。步行者256细胞中的尿苷转运被pCMBS抑制，IC 50（产生50%抑制的浓度）小于25 μ M，并且抑制作用很容易被β-巯基乙醇逆转。在S49细胞中，尿苷转运仅在高得多的pCMBS浓度下被抑制（IC 50约等于300 μ M）。在其他方面，步行者256和S49细胞中的核苷转运非常相似。Km和Vmax。尿苷转运的值几乎相同，并且两种细胞系的转运蛋白似乎接受宽范围的核苷作为底物。步行者256细胞中的尿苷转运是非集中的，并且不需要能量源。这些研究表明，核苷摄取在步行者256细胞介导的易化扩散机制，显着不同的S49细胞在其敏感性的运输抑制剂NBMPR和硫醇试剂pCMBS。
The characteristics of nucleoside transport were examined in Walker 256 rat carcinosarcoma and S49 mouse lymphoma cells. In Walker 256 cells the initial rates of uridine, thymidine and adenosine uptake were insensitive to the nucleoside transport inhibitor nitrobenzylthioinosine (NBMPR) (1 microM), but were partially inhibited by dipyridamole (10 microM), another inhibitor of nucleoside transport. In contrast, the transport of these nucleosides in S49 cells was completely blocked by both inhibitors. Nucleoside transport in Walker 256 and S49 cells also differed in its sensitivity to the thiol reagent p-chloromercuribenzenesulphonate (pCMBS). Uridine transport in Walker 256 cells was inhibited by pCMBS with an IC50 (concentration producing 50% inhibition) of less than 25 microM, and inhibition was readily reversed by beta-mercaptoethanol. In S49 cells uridine transport was only inhibited at much higher concentrations of pCMBS (IC50 approximately equal to 300 microM). In other respects nucleoside transport in Walker 256 and S49 cells were quite similar. The Km and Vmax. values for uridine transport were nearly identical, and the transporters of both cell lines appeared to accept a broad range of nucleosides as substrates. Uridine transport in Walker 256 cells was non-concentrative and did not require an energy source. These studies demonstrate that nucleoside uptake in Walker 256 cells is mediated by a facilitated-diffusion mechanism which differs markedly from that of S49 cells in its sensitivity to the transport inhibitor NBMPR and the thiol reagent pCMBS.