Activation of thin-fiber muscle afferents by a P2X agonist in cats

J Appl Physiol (1985). 2004 Mar;96(3):1166-9. doi: 10.1152/japplphysiol.01020.2003.

Abstract

The responses of group III and IV triceps surae muscle afferents to intra-arterial injection of alpha,beta-methylene ATP (50 microg/kg) was examined in decerebrate cats. We found that this P2X(3) agonist stimulated only three of 18 group III afferents but 7 of 9 group IV afferents (P < 0.004). The three group III afferents stimulated by alpha,beta-methylene ATP conducted impulses below 4 m/s. Pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid, a P2-receptor antagonist, prevented the stimulation of these afferents by alpha,beta-methylene ATP. We conclude that P2X(3) agonists stimulate only the slowest conducting group III muscle afferents as well as group IV afferents.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / drug effects*
  • Action Potentials / physiology
  • Adenosine Triphosphate / analogs & derivatives*
  • Adenosine Triphosphate / pharmacology*
  • Afferent Pathways / drug effects
  • Afferent Pathways / physiology
  • Animals
  • Cats
  • Muscle Fibers, Skeletal / drug effects*
  • Muscle Fibers, Skeletal / physiology
  • Purinergic P2 Receptor Agonists*
  • Receptors, Purinergic P2 / physiology

Substances

  • Purinergic P2 Receptor Agonists
  • Receptors, Purinergic P2
  • Adenosine Triphosphate
  • alpha,beta-methyleneadenosine 5'-triphosphate