The involvement of the opioidergic system in the antinociceptive mechanism of action of antidepressant compounds by Gray AM, Spencer PS, Sewell RD Division of Pharmacology, The Welsh School of Pharmacy, UWC, Cardiff, Wales.
Debate exists as to the nature of antidepressant-induced antinociception.
It is unclear whether antidepressants are inherently antinociceptive, are able to potentiate opioid antinociception or both. We have used the acetic acid induced abdominal constriction assay in mice to investigate antidepressant-induced antinociception. Similarly, morphine and aspirin were also effective antinociceptive agents in this nociceptive assay. Naloxone also shifted the morphine dose-response relationship to the right, by a factor of 2.62, whilst naltrindole had no effect upon morphine antinociception. Aspirin antinociception remained unaffected by both opioid antagonists.