Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2018
Comparative StudyMu-Opioid Receptors in Ganglia, But Not in Muscle, Mediate Peripheral Analgesia in Rat Muscle Pain.
Previous studies have demonstrated the participation of peripheral μ-opioid receptors (MOR) in the antinociceptive effect of systemically administered morphine and loperamide in an orofacial muscle pain model, induced by hypertonic saline, but not in a spinally innervated one, in rats. In this study, we determine whether this peripheral antinociceptive effect is due to the activation of MOR localized in the muscle, ganglia, or both. ⋯ The peripheral antinociceptive effect of systemically administered opioids may be due to the activation of MOR in ganglia. The greater expression of MOR in trigeminal ganglia could explain the higher antinociceptive effect of opioids in orofacial muscle pain than in spinal muscle pain. Therefore, peripheral opioids could represent a promising approach for the treatment of orofacial pain.