A suramin analog that acts as a highly selective, competitive, and reversible ATP-antagonist of P2X receptor (IC50/KB ~1 μM in smooth muscle). Effectively discriminates between P2Y and P2X receptors with no discernible effects on α1A adrenoceptors, adenosine A1 and A2B receptors, histamine H1, muscarinic M3 and neuronal nicotinic acetylcholine receptors. Displays a selectivity profile of P2X1 >P2X2 >P2X3 >P2X4 (IC50 = 19 nM, 770 nM, 1.62 μM and >300 μM, respectively) in Xenopus oocytes pre-incubated with ATP. In rat and human tissues, exhibits a potency profile of rat P2X1 > human P2X1 ? rat P2X2 > rat P2X3 ~human P2X7 ? human P2X4. Not degraded by ecto-nucleotidases.
A potent and selective P2X 1 antagonist (IC 50 = 19 nM). Displays good selectivity over P2X 2 ,(IC 50 = 0.76 μ M), P2X 3 (IC 50 = 1.62 μ M), P2X 4 (IC 50 > 300 μ M), P2Y receptors and ecto-nucleotidases.
