Antagonistic properties of the suramin analogue NF023 at heterologously expressed P2X receptors

Florentina Soto, Günter Lambrecht, Peter Nickel, Walter Stühmer, Andreas E. Busch

Research output: Contribution to journalArticle

83 Scopus citations

Abstract

The suramin analogue 8, 8'-(carbonylbis(imino-3,1-phenylene carbonylimino)bis(1,3,5-naphthalenetrisulfonic acid) (NF023) antagonizes in a competitive fashion P2X receptor-mediated responses in certain vascular and visceral smooth muscles. In the present study, the effect of NF023 on voltage-clamped Xenopus oocytes heterologously expressing homomultimeric P2X1-P2X4 as well as heteromultimeric P2X2/P2X3 receptors has been characterized. P2X1 receptors were most sensitive to inhibition by NF023 with IC50 values of 0.24 and 0.21 μM for the rat and human homologue, respectively. P2X3 receptors have an intermediate sensitivity with IC50 values of 8.5 and 28.9 μM for rat and human subtypes, respectively and P2X2 was the least sensitive subtype (IC50 > 50 μM). P2X4 receptors were insensitive to NF023 at concentrations up to 100 μM. Coexpression of rat P2X3 with rat P2X3 resulted in receptors whose sensitivity to NF023 was identical to that obtained for homomultimeric rat P2X3 receptors (αβmeATP as agonist; IC50 = 1.4 and 1.6 μM, respectively). NF023 inhibited P2X1 receptors in a voltage-insensitive manner. In addition, NF023 (5 and 30 μM) caused a shift of the concentration-response curve to the right without affecting the maximal response to ATP (K(B) = 1.1 ± 0.2 μM). Our results indicate that NF023 is a subtype-selective and surmountable antagonist at P2X1 receptors heterologously expressed in Xenopus oocytes.

Original languageEnglish
Pages (from-to)141-149
Number of pages9
JournalNeuropharmacology
Volume38
Issue number1
DOIs
StatePublished - Jan 1 1999
Externally publishedYes

Keywords

  • ATP
  • Competitive antagonism
  • NF023
  • P2X receptor
  • Suramin analogue

Fingerprint Dive into the research topics of 'Antagonistic properties of the suramin analogue NF023 at heterologously expressed P2X receptors'. Together they form a unique fingerprint.

  • Cite this