• Anesthesiology · Aug 1998

    Intrathecal neostigmine, but not sympathectomy, relieves mechanical allodynia in a rat model of neuropathic pain.

    • P Lavand'homme, H L Pan, and J C Eisenach.
    • Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157-1009, USA.
    • Anesthesiology. 1998 Aug 1; 89 (2): 493-9.

    IntroductionPain resulting from a usually nonpainful stimulus (allodynia) is a common characteristic of neuropathic pain. Among animal models of allodynia, tight ligature of lumbar spinal nerves has been of special interest because it has been reported to be relieved by sympathectomy. The purpose of this study was to determine whether spinal analgesic agents, which have opposite effects on sympathetic nervous system activity (clonidine decreases it and neostigmine increases it), have differing efficacy in this model.MethodsMale Sprague-Dawley rats were anesthetized, and the left L5 and L6 spinal nerves were ligated. At least 2 weeks later, a lumbar intrathecal or jugular intravenous catheter was inserted. Withdrawal threshold to mechanical stimulation of the hind paw was determined by application of von Frey filaments before surgery; after surgery; after intrathecal injection of clonidine, neostigmine, or their combination; after intravenous injection of phentolamine or guanethidine; and after surgical sympathectomy.ResultsSpinal nerve ligation reduced withdrawal threshold ipsilateral to the lesion. This allodynia was relieved by clonidine (50% block of allodynia at 20+/-1.2 microg and neostigmine (50% block of allodynia at 2+/-0.1 microg, and they interacted synergistically to block allodynia. Neither chemical nor surgical sympathectomy altered allodynia.DiscussionThese results disagree with previous observations that mechanical allodynia in this animal model depends on sympathetic nervous system activity. Therefore, intrathecally administered analgesic agents, one that reduces sympathetic outflow from the spinal cord (clonidine) and one that increases it (neostigmine), were similarly effective in this model.

      Pubmed     Free full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…