Novel purinergic sensitivity develops in injured sensory axons following sciatic nerve transection in rat.
Teased fibers were made from 153 spontaneous A afferents ending in sciatic nerve end neuromas of 3-14 days standing, 21 A afferents from intact sensory endings in the contralateral sciatic nerve, and 50 intact A afferents from the sciatic nerve in intact rats. Ninety-two percent of the injured fibers responded to adenosine 5'-triphosphate (ATP) (i.v.). However, few fibers from the contralateral nerve or nerves from intact animals responded to ATP. P2 receptor antagonist suramin or reactive blue 2 blocked the ATP-induced response in 76% of the fibers tested, whereas the P1 receptor antagonist aminophylline blocked the ATP-evoked effect in only 18% of the fibers tested. Sympathectomy did not affect the ATP-induced effects in injured axons. Close-arterial injection of ATP caused similar results as i.v. injection of ATP. The present study suggests that a novel purinergic sensitivity is developed at the injury site after sciatic nerve transection in rats, which may play a role in neuropathic pain under some conditions such as sympathetic activation.
Chen
Y
Y
Shanghai Institute of Physiology, Shanghai Brain Research Institute, Chinese Academy of Sciences, Shanghai 200031, P.R., China.
Zhang
Y H
YH
Zhao
Z Q
ZQ
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D004347:Drug Interactions / Q000502:physiology; D008297:Male; D009410:Nerve Degeneration / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D009413:Nerve Fibers, Myelinated / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009431:Neural Conduction / Q000187:drug effects / Q000502:physiology; D009437:Neuralgia / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009463:Neuroma / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009475:Neurons, Afferent / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D058915:Purinergic P1 Receptor Antagonists; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D012584:Sciatic Nerve / Q000293:injuries* / Q000378:metabolism / Q000503:physiopathology; D020426:Sciatic Neuropathy / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology
D058915:Purinergic P1 Receptor Antagonists; D058919:Purinergic P2 Receptor Antagonists; D018047:Receptors, Purinergic P1; D018048:Receptors, Purinergic P2; D000255:Adenosine Triphosphate