RT Journal Article SR Electronic T1 A Common Basis for Inhibition of Nucleoside Transport by Dipyridamole and Nitrobenzylthioinosine? JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 40 OP 44 VO 18 IS 1 A1 ALAN R. P. PATERSON A1 EDA Y. LAU A1 EWA DAHLIG A1 CAROL E. CASS YR 1980 UL http://molpharm.aspetjournals.org/content/18/1/40.abstract AB 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 [3H]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.