Analgesic mechanism of electroacupuncture in an arthritic pain model of rats: a neurotransmitter study.
OBJECTIVE
We investigated what kinds of neurotransmitters are related with electroacupuncture (EA) analgesia in an arthritic pain model of rats.


METHODS
One hundred rats were assigned to six groups: control, EA, opioid, adrenergic, serotonin and dopamine group. A standardized model of inflammatory arthritis was produced by injecting 2% carrageenan into the knee joint cavity. EA was applied to an acupoint for 30 min in all groups except fo the control group. In the opioid, adrenergic, serotonin and dopamine groups, each receptor antagonist was injected intraperitoneally to their respective group before initiating EA.


RESULTS
In the opioid receptor antagonist group, adrenergic receptor antagonist group, serotonin receptor antagonist group, dopamine receptor antagonist group and the control group weight-bearing force decreased significantly from 30 min to 180 min after EA in comparison with the EA group.


CONCLUSIONS
The analgesic effects of EA are related to opioid, adrenergic, serotonin and dopamine receptors in an arthritic pain model of rats.
Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea.
Young-Chul
YC
Yoo
Jin Hwan
JH
Oh
Tae Dong
TD
Kwon
Yeong Kyu
YK
Lee
Sun Joon
SJ
Bai
D015667:Acupuncture Analgesia / Q000379:methods*; D018674:Adrenergic Antagonists / Q000627:therapeutic use; D000818:Animals; D001168:Arthritis / Q000139:chemically induced / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D002351:Carrageenan / Q000633:toxicity; D018492:Dopamine Antagonists / Q000627:therapeutic use; D015671:Electroacupuncture / Q000379:methods*; D008297:Male; D009292:Narcotic Antagonists; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010146:Pain / Q000188:drug therapy / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011941:Receptors, Adrenergic / Q000378:metabolism; D011954:Receptors, Dopamine / Q000378:metabolism; D011957:Receptors, Opioid / Q000378:metabolism; D011985:Receptors, Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists / Q000627:therapeutic use
D018674:Adrenergic Antagonists; D018492:Dopamine Antagonists; D009292:Narcotic Antagonists; D018377:Neurotransmitter Agents; D011941:Receptors, Adrenergic; D011954:Receptors, Dopamine; D011957:Receptors, Opioid; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D002351:Carrageenan