Elsevier

Neuroscience Letters

Volume 199, Issue 2, 20 October 1995, Pages 111-114
Neuroscience Letters

Systemic and supraspinal, but not spinal, opiates suppress allodynia in a rat neuropathic pain model

https://doi.org/10.1016/0304-3940(95)12034-2Get rights and content

Abstract

The effects of intraperitoneal (IP), intracerebroventricular (ICV) and intrathecal (IT) opiates were studied in the rat neuropathic pain model of Kim and Chung. Dose dependent reduction of allodynia was observed after IP and ICV morphine, but not after IT morphine, IT or ICV c[d-pen2 d-pen5]enkephalin (DPDPE) (δ agonist), or IT or ICV U50488H (κ agonist). The effects of ICV morphine were blocked by IP naloxone, but not by IT methysergide, phentolamine or 8-sulfophenyltheophylline. Catalepsy (immobility) was observed after IT, ICV and IT morphine but this was not reliably associated with a reduction of allodynia. IP and ICV morphine may thus reduce tactile allodynia via supraspinal, but not spinal, μ opioid receptors.

References (21)

  • S. Arnér et al.

    Lack of analgesic effect of opioids on neuropathic and idiopathic forms of pain

    Pain

    (1988)
  • R. Bandler et al.

    Integration of somatic and autonomic reactions within the midbrain periaqueductal grey: viscerotopic, somatotopic and functional organization

    Prog. Brain Res.

    (1991)
  • P.J. Camarata et al.

    Characterization of the spinal adrenergic receptors mediating the spinal effects produced by the microinjection of morphine into the periaqueductal gray

    Brain Res.

    (1985)
  • S.R. Chaplan et al.

    Quantitative assessment of allodynia in the rat paw

    J. Neurosci. Methods

    (1994)
  • S.R. Chaplan et al.

    Role of voltage-dependent calcium channel subtypes in experimental tactile allodynia

    J. Pharmacol. Exp. Ther.

    (1994)
  • S.R. Chaplan et al.

    Intrathecal dextrorphan suppresses allodynia in a rat surgical neuropathy model by a spinal mechanism

    Anesthesiology

    (1993)
  • G.E. DeLander et al.

    Involvement of adenosine in antinociception produced by spinal or supraspinal receptor-selective opioid agonists: dissociation from gastrointestinal effects in mice

    J. Pharmacol. Exp. Ther.

    (1992)
  • H.L. Fields et al.

    Brainstem control of spinal pain-transmission neurons

    Annu. Rev. Physiol.

    (1978)
  • S.L. Jones et al.

    Inhibition of spinal nociceptive transmission from the midbrain, pons and medulla in the rat: activation of descending inhibition by morphine, glutamate and electrical stimulation

    Brain Res.

    (1988)
  • S.H. Kim et al.

    An experimental model for peripheral neuropathy produced by segmental spinal nerve ligation in the rat

    Pain

    (1992)
There are more references available in the full text version of this article.

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This work was supported in part by DA02110 (TLY).

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