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

Br J Pharmacol. 1998 Aug;124(7):1463-6. doi: 10.1038/sj.bjp.0702001.


1. P2X receptor activation by alpha,beta-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 microM alpha,beta-meATP (an approximately EC90 concentration) with an IC50 of approximately 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 alpha,beta-meATP induced contractions with an IC50 of approximately 30 microM 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / analogs & derivatives*
  • Adenosine Triphosphate / pharmacology
  • Animals
  • In Vitro Techniques
  • Ion Channels / antagonists & inhibitors*
  • Mesenteric Arteries / drug effects*
  • Mesenteric Arteries / metabolism
  • Purinergic P2 Receptor Antagonists*
  • Rats


  • Ion Channels
  • Purinergic P2 Receptor Antagonists
  • 2',3'-O-(2,4,6-trinitro-cyclohexadienylidine)adenosine 5'-triphosphate
  • Adenosine Triphosphate