S-(4-Nitrobenzyl)-6-thioinosine is a nucleoside analog that competitively inhibits the equilibrative nucleoside transporter 1 (Kd = 0.1-1.0 nM; IC50s = 4.6 and 3.6 nM in rat and human, respectively). It blocks adenosine flux across the plasma membrane, thereby potentiating the interaction of extracellular adenosine with purinoreceptors, which can affect cardiac signaling associated with adenosine.
