A common basis for inhibition of nucleoside transport by dipyridamole and nitrobenzylthioinosine?
A common basis for inhibition of nucleoside transport by dipyridamole and nitrobenzylthioinosine?
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双嘧达莫和硝基苄硫肌苷抑制核苷转运的共同基础？
作者：
A. Paterson;E. Lau;E. Dahlig;C. Cass
尿苷单层培养的HeLa细胞的运输被抑制硝基苄硫代肌苷，双嘧达莫，和lidoflazine。双嘧达莫对核苷转运的抑制作用不明显，而硝基苄硫代肌苷对核苷转运的抑制作用呈双相量效曲线。双嘧达莫和利多夫嗪干扰高亲和力结合[ 3 H]nitrobenzylthioinosine的HeLa细胞在一个明显的竞争方式;值为1，30，和300 nM的解离常数，分别为nitrobenzylthioinosine，双嘧达莫，和利多夫嗪。在后者的高亲和力结合位点与nitrobenzylthioinosine明显的竞争表明，双嘧达莫和利多夫嗪抑制核苷转运与这些网站的相互作用。
Transport of uridine by monolayer cultures of HeLa cells was inhibited by nitrobenzylthioinosine, dipyridamole, and lidoflazine. Biphasic concentration-effect curves were obtained for inhibition of nucleoside transport by nitrobenzylthioinosine, but not for inhibition by dipyridamole. Dipyridamole and lidoflazine interfered with high-affinity binding of [ 3 H]nitrobenzylthioinosine to HeLa cells in an apparently competitive fashion; values of 1, 30, and 300 nM were obtained for dissociation constants, respectively, for nitrobenzylthioinosine, dipyridamole, and lidoflazine. The apparent competition with nitrobenzylthioinosine at the latter’s high-affinity binding sites suggests that dipyridamole and lidoflazine inhibit nucleoside transport by interaction with these sites.