Spinal serotonin IA and IC/2 receptors mediate supraspinal mu opioid-induced analgesia.
Intracerebroventricular (i.c.v.) injection of highly selective mu opioid receptor agonist ohmefentanyl (OMF) to rats produced dose-dependent antinociception as assessed with the tail flick test. This analgesia could be blocked by intrathecal (i.t.) injection of the 5-HT1A receptor antagonist spiperone or the 5-HT1C/2 receptor antagonist mianserin, but not by the 5-HT2 receptor antagonist 1-NP or the 5-HT3 receptor antagonist ICS 205-930. The results suggest that the descending 5-HT system is involved in mediating spinal mu opioid analgesia via spinal 5-HT1A and 5-HT1C/2 receptors.
Xu
W
W
Neuroscience Research Center, Beijing Medical University, China.
Cui
X
X
Han
J S
JS
D000698:Analgesia; D000818:Animals; D001921:Brain / Q000502:physiology*; D005283:Fentanyl / Q000031:analogs & derivatives / Q000494:pharmacology; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time; D017450:Receptors, Opioid, mu / Q000819:agonists*; D011985:Receptors, Serotonin / Q000145:classification / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013116:Spinal Cord / Q000378:metabolism*
D017450:Receptors, Opioid, mu; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; C037016:F 7302; D005283:Fentanyl