Binding sites of mu receptor increased when acupuncture analgesia was enhanced by droperidol: an autoradiographic study.
OBJECTIVE
To study if mu receptor participates in the process of potentiation of droperidol (Dro) on acupuncture analgesia (AA).


METHODS
Autoradiographic technic was used. Ohmefentanyl, a highly selective ligand of mu receptors, was used in radio-receptor binding assay in Sprague-Dawley rat brain sections.


RESULTS
The binding sites of [beta-3H, p-benzoyl-3H]ohmefentanyl were increased greatly in many nuclei of rat brain after AA, and were further increased when AA was enhanced by Dro. Higher increase was seen in caudate nucleus, accumbens, periaqueductal gray (PAG), interpeduncular nucleus, amygdala (P < 0.01 vs rats treated with electroacupuncture alone); moderate increase was noted in thalamus, lateral area of hypothalamus, spinal dorsal horn (P < 0.01 or 0.05); slight increase appeared in septum, preoptic area, hippocampus, substantia nigra (P < 0.05).


CONCLUSIONS
Mu opioid receptors mediated the Dro-induced enhancement of AA.
Zhu
C B
CB
Department of Neurobiology, Shanghai Medical University, China.
Li
X Y
XY
Zhu
Y H
YH
Xu
S F
SF
D015667:Acupuncture Analgesia; D000700:Analgesics / Q000378:metabolism; D000818:Animals; D001345:Autoradiography; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D004329:Droperidol / Q000494:pharmacology*; D005283:Fentanyl / Q000031:analogs & derivatives / Q000378:metabolism; D008297:Male; D017288:Pain Threshold / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000378:metabolism*
D000700:Analgesics; D017450:Receptors, Opioid, mu; C037016:F 7302; D004329:Droperidol; D005283:Fentanyl