2',3'-O-(2,4,6,- trinitrophenyl) adenosine 5'-triphosphate (TNP-ATP)-a nanomolar affinity antagonist at rat mesenteric artery P2X receptor ion channels

摘要

P2X receptor activation by α,β-meATP evoked inward currents in acutely dissociated rat mesenteric artery smooth muscle cells and contractions of whole artery rings. The selective P2X_1 and P2X_3 receptor antagonist TNP-ATP inhibited P2X receptor mediated inward Currents in response to 3 μM α,β-meATP(an ～EC_90 concentration) with an IC_50 of ～2 nM. This Provides further evidence that the P2X receptor underlying membrane depolarisation associated with P2X receptor activation can be accounted for by the expression of P2X_1 receptors. TNP-ATP inhibited α,β-meATP induced contractions with an IC_50 of ～30μM and has non-specific Effects on smooth muscle contraction.