Activation of thin-fiber muscle afferents by a P2X agonist in cats.
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.
Hanna
Ramy L
RL
Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis 95616, USA.
Kaufman
Marc P
MP
D000200:Action Potentials / Q000187:drug effects* / Q000502:physiology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology*; D000344:Afferent Pathways / Q000187:drug effects / Q000502:physiology; D000818:Animals; D002415:Cats; D018485:Muscle Fibers, Skeletal / Q000187:drug effects* / Q000502:physiology; D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2 / Q000502:physiology
D058910:Purinergic P2 Receptor Agonists; D018048:Receptors, Purinergic P2; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate