PPADS (pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid) is a selective purinergic

P2X The ATP-gated P2X receptor cation channel familyTC# 1.A.7, or simply P2X receptor family, consists of cation-permeable ligand-gated ion channels that open in response to the binding of extracellular adenosine 5'-triphosphate ( ATP). They belong ...

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

. It is able to block contractions of rabbit vas deferens induced by ATP or α,β,methylene-ATP. It appears to be relatively selective for P2X receptors, having no appreciable activity at α₁ adrenergic, muscarinic M₂ and M₃, histamine H₁, and adenosine A₁ receptors.

References

Azo compounds Organophosphates Pyridines Sulfonic acids {{genito-urinary-drug-stub