Evidence for the Presence of P2y and P2x Receptors With Different Functions in Mouse Stomach

Eur J Pharmacol. 2005 Apr 18;513(1-2):135-40. doi: 10.1016/j.ejphar.2005.01.052. Epub 2005 Apr 7.

Abstract

To clarify the function of P2 receptor subtypes in mouse stomach, the motor responses to ATP, alpha,beta-methyleneATP (alpha,beta-MeATP), P2X receptor agonist, 2-methylthioATP (2-MeSATP), P2Y receptor agonist, and the effects of the desensitisation of P2X receptors with alpha,beta-MeATP and of P2Y receptors with ADPbetaS were analysed recording the endoluminal pressure from whole-organ. ATP-induced relaxation was antagonised by suramin, non-selective P2 receptor antagonist, by desensitisation of P2Y receptors with ADPbetaS, and increased by desensitisation of P2X receptors with alpha,beta-MeATP. alpha,beta-MeATP produced biphasic responses: relaxation, reduced by P2X- or P2Y desensitisation, and contraction, almost abolished by P2X desensitisation and potentiated by P2Y desensitisation. 2-MeSATP induced relaxation, which was antagonised by P2Y desensitisation and increased by P2X desensitisation. Tetrodotoxin increased the relaxation induced by purines and deeply antagonised the contraction to alpha,beta-MeATP. Our results suggest that in mouse stomach are present muscular P2Y receptors, subserving relaxation, and neuronal presynaptic P2X receptors, mediating contraction.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Diphosphate / analogs & derivatives*
  • Adenosine Diphosphate / pharmacology
  • Adenosine Triphosphate / analogs & derivatives*
  • Adenosine Triphosphate / pharmacology
  • Animals
  • Dose-Response Relationship, Drug
  • In Vitro Techniques
  • Mice
  • Mice, Inbred C57BL
  • Muscle Contraction / drug effects
  • Muscle Relaxation / drug effects
  • Receptors, Purinergic P2 / physiology*
  • Receptors, Purinergic P2X
  • Stomach / drug effects
  • Stomach / physiology*
  • Tetrodotoxin / pharmacology
  • Thionucleotides / pharmacology

Substances

  • Receptors, Purinergic P2
  • Receptors, Purinergic P2X
  • Thionucleotides
  • adenosine 5'-O-(2-thiodiphosphate)
  • Tetrodotoxin
  • Adenosine Diphosphate
  • Adenosine Triphosphate
  • alpha,beta-methyleneadenosine 5'-triphosphate
  • 2-methylthio-ATP