NF 279 is 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 effect 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.
