These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Lumbar sympathectomy failed to reverse mechanical allodynia- and hyperalgesia-like behavior in rats with L5 spinal nerve injury.
    Author: Ringkamp M, Eschenfelder S, Grethel EJ, Häbler HJ, Meyer RA, Jänig W, Raja SN.
    Journal: Pain; 1999 Feb; 79(2-3):143-53. PubMed ID: 10068160.
    Abstract:
    The L5 spinal nerve ligation model of neuropathic pain in rats has been proposed as a model for sympathetically maintained pain (SMP) based on the effects of surgical or chemical sympathectomy on nerve injury induced behavior. In an attempt to confirm that the lesion produces an animal model of SMP, surgical sympathectomies were independently conducted in two different laboratories (Johns Hopkins and University Kiel) using male Sprague-Dawley (n = 30) or Wistar rats (n = 14). The L5 spinal nerve was ligated or cut and ligated. Using von Frey hairs, paw withdrawal threshold and incidence of paw withdrawal were tested concurrently before and after the sympathectomy. The sympathectomy was either verified by (a) glyoxylic acid staining of peripheral blood vessels of the hindpaw or (b) skin temperature measurements of the hindpaws. To blind the experimenter, surgeries and behavioral tests were performed by two different investigators and a sham sympathectomy was performed at Johns Hopkins. Decreased paw withdrawal thresholds and increased frequencies of paw withdrawal on the lesioned side were observed after the L5 lesion. Thus, the L5 spinal nerve ligation resulted in behavioral signs of allodynia and hyperalgesia to mechanical stimuli. Lumbar surgical sympathectomy 1-3 weeks after the lesion or prior to lesion with bilateral removal of the sympathetic ganglia L2-L4, however, did not reverse or prevent the behavioral changes induced by the nerve injury. The lack of effect of the sympathectomies was independent of the testing paradigm used. Experiments in Wistar and Sprague-Dawley rats yielded the same results. Potential reasons for the discrepancies between the present study and earlier reports are discussed. These results indicate that an L5 spinal nerve injury rat model is not a reliable model for SMP.
    [Abstract] [Full Text] [Related] [New Search]