Benzodiazepine inhibition of site-specific binding of nitrobenzylthioinosine, an inhibitor of adenosine transport

A number of benzodiazepines were tested for their ability to inhibit the site-specific binding of nitrobenzylthioinosine to the nucleoside transport system in human erythrocytes. Dipyridamole, a recognized inhibitor of nucleoside transport, inhibited binding in a competitive manner. Benzodiazepines also inhibited nitrobenzylthioinosine binding competitively, but were considerably less potent in that respect than dipyridamole. The low affinities of the benzodiazepines for the erythrocyte transport system suggest that significant inhibition of nucleoside transport may not occur at anxiolytic concentrations. However, at higher concentrations, some benzodiazepines would appear to have the potential to inhibit adenosine transport via interaction with the transport-inhibitory site.