Table 1.

P2X receptors

	Affinity ATP (EC50)	Agonists	Antagonists	Inhibition by divalent cationsa
P2x1	1 μM	BzATP>ATP = 2MeSATP>α,β-meATP	Suramin, NF023, PPADS, TNP-ATP	H+, Zn 2+ ↓
			IsoPPADS, NF449, Phenol Red, PPNDS
			oATP (reversible)
P2x2	10 μM	ATP>ATPγS≥2MeSATP>>>αβmeATP	Suramin, NF023, PPADS	Ca2+ ↓
			RB-2, NF279	Zn2+, Cu2+, H+ ↑
P2x3	1 μM	BzATP≥2meSATP≥ATP≥αβmeATP	Suramin, NF023, PPADS, TNP-ATP	Ca2+, H+ ↓
			IsoPPADS, Phenol Red, A3174	Zn2+ ↑
P2x4	10 μM	ATP>2meSATP>α,β-meATP	TNP-ATP (weak), BBG (weak)	H+, Cu2+ ↓
		Ivermectin (potentiates)		Zn2+↑
P2x5	10 μM	ATP=2MeSATP=ATPγγS>αβmeATP	Suramin, PPADS, BBG
P2x6	10 μM	ATP>2MeSATP>ADP
P2x7	>100 μM	BzATP>>ATP>>UTP>>2meSATP>>αβmeATP	oATP (irreversible), BBG, KN-62b, NF-279, PPADSa, A-438079, A-740003	Ca2+, Mg2+, Cu2+, Zn2+, H+↓

Adapted from Bianchi et al. [107], North [15], Jacobson et al. [85], Burnstock [3]

^aEffect of divalent cations on the current flow through the receptor ion channel. Downward-facing arrow Decreases, upward-facing arrow increases

^bSpecies differences (rat vs. human)

BBG Brilliant blue G, BzATP 2′-and 3′-O-(4-benzoyl-benzoyl)-ATP, α,β-meATP α,β˜-methylene ATP, 2-MeSATP 2-metylthio ATP, ATPγS 5′-O-(3-thiotriphosphate), KN-62 1-[N,O-bis(5-isoquinolinesulfonyl)-N-methyl-l-tyrosyl]-4-phenylpiperazine, NF023 8,8′-(carbonylbis(imino-3,1-phenylenecarbonylimino))-bis(naphthalene-1,3,5-trisulfonic acid)-hexasodium salt, NF449 4,4′,4″,4″′-(carbonylbis(imino-5,1,3-benzenetriylbis(carbonylimino)))tetrakis-benzene-1,3-disulfonic acidoctasodium salt, PPADS pyridoxal-phosphate-6-azophenyl-2′,4′-disulfonic acid, RB2 reactive blue, oATP periodate-oxidized ATP, TNP-ATP trinitrophenyl-substituted ATP