The μ‐opioid receptor agonist morphine, but not agonists at δ‐ or κ‐opioid receptors, induces peripheral antinociception mediated by cannabinoid receptors

Abstract

Our results provide evidence for the involvement of endocannabinoids, in the peripheral antinociception induced by the mu-opioid receptor agonist morphine. The release of cannabinoids appears not to be involved in the peripheral antinociceptive effect induced by kappa- and delta-opioid receptor agonists.