Specific down-regulation of spinal mu-opioid receptor and reduced analgesic effects of morphine in mice with postherpetic pain.

@article{Takasaki2006SpecificDO,
  title={Specific down-regulation of spinal mu-opioid receptor and reduced analgesic effects of morphine in mice with postherpetic pain.},
  author={Ichiro Takasaki and Hiroshi Nojima and Kimiyasu Shiraki and Yasushi Kuraishi},
  journal={European journal of pharmacology},
  year={2006},
  volume={550 1-3},
  pages={62-7}
}
The analgesic effects of opioid agonists and the expression of mu- and kappa-opioid receptors were compared between mice with herpetic pain and those with postherpetic pain induced by herpetic virus inoculation. Morphine inhibited herpetic pain more effectively than postherpetic pain. Intrathecal injection reduced the analgesic effects of morphine on postherpetic pain, but intracerebroventricular injection did not. The kappa-opioid receptor agonist nalfurafine suppressed herpetic and… CONTINUE READING