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British Journal of Pharmacology logoLink to British Journal of Pharmacology
. 1998 Aug;124(7):1463–1466. doi: 10.1038/sj.bjp.0702001

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

C J Lewis 1, A Surprenant 2, R J Evans 1,3,*
PMCID: PMC1565549  PMID: 9723959

Abstract

  1. 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.

  2. The selective P2X1 and P2X3 receptor antagonist TNP-ATP inhibited P2X receptor mediated inward currents in response to 3 μM α,β-meATP (an ∼EC90 concentration) with an IC50 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 P2X1 receptors.

  3. TNP-ATP inhibited α,β-meATP induced contractions with an IC50 of ∼30 μM and had non-specific effects on smooth muscle contraction.

  4. The reduced potency of TNP-ATP in whole tissue experiments probably reflects the breakdown of TNP-ATP by nucleotidases. Thus, TNP-ATP is of limited use in whole tissue experiments as a P2X receptor antagonist.

Keywords: P2X receptors, ATP, artery, contractions, electrophysiology, antagonist

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