• Reg Anesth Pain Med · May 2005

    Peripheral block of the hyperpolarization-activated cation current (Ih) reduces mechanical allodynia in animal models of postoperative and neuropathic pain.

    • Carine Dalle and James C Eisenach.
    • Center for the Study of Pharmacologic Plasticity in the Presence of Pain, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1009, USA.
    • Reg Anesth Pain Med. 2005 May 1; 30 (3): 243-8.

    Background And ObjectivesBlock of the hyperpolarization-activated inward current (I h) reduces excitability of peripheral axons during stimulation and decreases ectopic discharges in axotomized sensory neurons. Changes in I h expression in DRG neurons have been suggested to partially underlie sensitization after nerve injury and inflammation. We hypothesized that peripheral block of I h on axons would produce an antiallodynic effect in postoperative as well as neuropathic conditions, and we tested perineural administration of ZD 7288, a specific blocker of I h , on pain-associated behavior in animal models of neuropathic and postoperative pain.MethodsUnder halothane anesthesia, partial sciatic nerve injury or hind-paw incision were performed on adult male rats as previously described. Mechanical allodynia was inferred by demonstration of a decrease in paw withdrawal threshold by application of calibrated von Frey filaments. After surgery, animals received either a saline or a ZD 7288 solution either by sciatic perineural injection or by intraplantar injection.ResultsPerineural administration of ZD 7288 (100 microM) significantly reduced mechanical allodynia induced by partial sciatic nerve injury and hind-paw incision. Saline and 10 microM of ZD 7288 had no significant effect on mechanical allodynia. Contralateral administration of ZD 7288, 100 microM, did not affect ipsilateral paw withdrawal threshold after nerve injury. Intraplantar injection of ZD 7288 failed to reduce mechanical allodynia after nerve injury. Sedation and motor effects were not observed.ConclusionsThe current study shows that peripheral block of I h produces an antiallodynic effect, which suggests that I h channels represent a novel target for nerve block treatment of postoperative and neuropathic pain.

      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…