THE EFFECTS OF MORPHINE ON CARRAGEENAN-INDUCED SPINAL C-FOS EXPRESSION ARE COMPLETELY BLOCKED BY BETA-FUNALTREXAMINE, A SELECTIVE MU-OPIOIDRECEPTOR ANTAGONIST
P. Honore et al., THE EFFECTS OF MORPHINE ON CARRAGEENAN-INDUCED SPINAL C-FOS EXPRESSION ARE COMPLETELY BLOCKED BY BETA-FUNALTREXAMINE, A SELECTIVE MU-OPIOIDRECEPTOR ANTAGONIST, Brain research, 732(1-2), 1996, pp. 242-246
We have demonstrated that pre-administered morphine (3 mg/kg, i.v.) de
creased spinal c-Fos expression induced 2 h after intraplantar carrage
enin (55 +/- 5% reduction, P < 0.0001). These effects were completely
blocked by pre-administered beta-funaltrexamine (10 mg/kg, i.v., 24 h
prior to stimulation) a selective long-lasting mu-opioid receptor anta
gonist. In conclusion, these results clearly demonstrate that the effe
cts of morphine on noxiously-evoked spinal c-Fos expression are essent
ially mediated via mu-opioid receptors.