Differential effects of selective mu-, kappa- and delta-opioid antagonists on electroshock seizure threshold in mice.

Abstract

The effects of the selective opioid antagonists cyprodime (mu; 1, 3, 10, 30 mg/kg IP), norbinaltorphimine (kappa; 3, 10, 30 mg/kg IP) and naltrindole (delta; 0.3, 1, 3, 10 mg/kg IP) on electroshock seizure threshold in mice were compared with those of the universal opioid antagonist naloxone (0.3, 1, 10 mg/kg IP). Seizure threshold was increased by mu-receptor blocking doses of both cyprodime and naloxone, unaltered by norbinaltorphimine and decreased (in a dose-related manner) by all doses of naltrindole. The effects of naltrindole were similar to those of the established pro-convulsant agent bicuculline (1 mg/kg IP); however, naloxone and cyprodime produced relatively small increases in seizure threshold when compared with phenytoin (doses up to 30 mg/kg IP). The differential effects of mu-, kappa- and delta-receptor antagonists obtained in this study suggest that electroshock seizure threshold in mice may be controlled, at least in part, by a balance between endogenous opioids acting either pro-convulsantly through mu-receptors or anti-convulsantly via delta-receptors.

• Authors: H C Jackson, D J Nutt
• Journal: Psychopharmacology (Psychopharmacology (Berl)) Vol. 103 Issue 3 Pg. 380-3 ( 1991) ISSN: 0033-3158 [Print] Germany
• PMID: 1647539 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Anticonvulsants
• Indoles
• Morphinans
• Narcotic Antagonists
• Receptors, Opioid
• Receptors, Opioid, delta
• Receptors, Opioid, kappa
• Receptors, Opioid, mu
• cyprodime
• Naloxone
• norbinaltorphimine
• gamma-Aminobutyric Acid
• Naltrexone
• Phenytoin
• naltrindole
• Bicuculline

Topics

• Animals
• Anticonvulsants
• Bicuculline (pharmacology)
• Dose-Response Relationship, Drug
• Electroshock
• Indoles (pharmacology)
• Male
• Mice
• Mice, Inbred Strains
• Morphinans (pharmacology)
• Naloxone (pharmacology)
• Naltrexone (analogs & derivatives, pharmacology)
• Narcotic Antagonists (pharmacology)
• Phenytoin (pharmacology)
• Receptors, Opioid (drug effects)
• Receptors, Opioid, delta
• Receptors, Opioid, kappa
• Receptors, Opioid, mu
• gamma-Aminobutyric Acid (pharmacology)