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The Sciatic Nerve Cuffing Model of Neuropathic Pain in Mice
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The role of delta-opioid receptor subtypes in neuropathic pain

J Mika1, R Przewłocki, B Przewłocka

  • 1Department of Molecular Neuropharmacology, Institute of Pharmacology, Polish Academy of Sciences, 12 Smetna Street, 31-343 Cracow, Poland.

European Journal of Pharmacology
|March 14, 2001
PubMed

Insights

Spinal administration of delta-opioid receptor agonists [D-Pen(2), D-Pen(5)]enkephalin (DPDPE) and deltorphin II demonstrated significant antiallodynic and antinociceptive effects in a rat neuropathic pain model.

Area of Science:

  • Neuroscience
  • Pharmacology
  • Pain Research

Background:

  • Delta-opioid receptors are implicated in spinal antinociception.
  • Neuropathic pain models are crucial for evaluating pain therapies.

Purpose of the Study:

  • To investigate the spinal antinociceptive and antiallodynic effects of delta(1)- and delta(2)-opioid receptor agonists and antagonists.
  • To assess these effects after acute and chronic intrathecal administration in a rat neuropathic pain model.

Main Methods:

  • Intrathecal administration of delta(1)-opioid receptor agonist DPDPE and delta(2)-opioid receptor agonist deltorphin II in rats with sciatic nerve crush injury.
  • Assessment of antiallodynic effects using cold-water allodynia tests and antinociceptive effects using tail-flick latency tests.
  • Administration of specific antagonists (BNTX for DPDPE, 5'NTII for deltorphin II) to confirm receptor involvement.
  • Evaluation of effects after both acute and chronic drug administration.

Main Results:

  • Both DPDPE and deltorphin II dose-dependently antagonized cold-water allodynia and increased tail-flick latency.
  • The effects of DPDPE were blocked by BNTX, and deltorphin II's effects were blocked by 5'NTII, confirming receptor specificity.
  • Chronic administration of both agonists led to significant and prolonged antiallodynic effects.

Conclusions:

  • Delta-opioid receptor agonists DPDPE and deltorphin II exhibit significant antiallodynic and antinociceptive actions at the spinal cord level.
  • Both delta(1)- and delta(2)-opioid receptor subtypes play comparable roles in managing neuropathic pain.
  • These findings suggest that agonists targeting both delta(1)- and delta(2)-opioid receptors are promising candidates for neuropathic pain therapy.

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