Elsevier

Neuroscience Letters

Volume 190, Issue 2, 5 May 1995, Pages 137-139
Neuroscience Letters

Sigma antagonists potentiate opioid analgesia in rats

https://doi.org/10.1016/0304-3940(95)11504-PGet rights and content
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Abstract

In mice, activation of sigma, receptors antagonizes opioid analgesia. Sigma antagonists potentiate opioid analgesia, implying that the anti-opioid sigma system is tonically active. Co-administration of haloperidol with the mu opioid morphine, the kappa1 analgesic U50,488H or the kappa3 agonist naloxone benzoylhydrazone enhances the analgesic activity of all agents. The effect results from sigma receptor blockade since (−)sulpiride, a selective D2 antagonist which does not block sigma receptors, is inactive.

Keywords

Opioid analgesia
Sigma, receptors

Cited by (0)

We thank Drs. R. Rapaka of the Research Technology Branch of NIDA and J. Posner for their assistance with these studies. This work is supported, in part, by a grant from the National Institute on Drug Abuse (DA06241) to GWP and a core grant to MSKCC from the National Cancer Institute (CA08748). CCC is supported by a Fellowship from Cathay General Hospital, Taipei, Taiwan. GWP is supported by a Research Scientist Development Award from the National Institute on Drug Abuse (DA00220).