[Analgesic effect of CQM on prosopalgia model rats and its impact on exciting amino acid neurotransmitters].
OBJECTIVE
To observe the analgesic effect of CQM on photochemically-induced prosopalgia model rats, and discuss its impact on the exciting amino acid neurotransmitter-glutamate (Glu).


METHODS
Male SD rats were randomly divided into the sham operation group and the prosopalgia group. And the latter was subdivided into the model group, the gabapentin group (100 mg kg(-1)), and the CQM low-dose (35 mg x kg(-1)) and CQM high-dose (70 mg x kg(-1)) groups. The mechanical allodynia test was adopted to evaluate the pain behavior of rats, and reflect the efficacy with the mechanical withdrawal thresholds. The rat striatum extra-cellular fluid was collected by brain micro-dialysis. The Glu level of samples was measured by high performance liquid chromatography-fluorescene detector (HPLC-FLD).


RESULTS
Compared to the control group, the threshold of the mechanical allodynia of the IoN injury group was decreased significantly (P < 0.05), and the concentration of Glu was increased dramatically (P < 0.05). Compared to the model group, the mechanical allodynia of photochemically-induced prosopalgia model rats increased significantly (P < 0.01), with a notable increase in brain Glu concentration (P < 0.05). Compared with the model group, all of mechanical withdrawal thresholds increased. Among them, the CQM high-dose group showed a remarkably growth at three time points (P < 0.05), with the maximum up to (23 +/- 7.3) g. And the gabapentin group showed a remarkably growth at two time points (P < 0.05), with the maximum up to (20.5 +/- 9.2) g. All of the drug groups showed significantly lower Glu concentrations in rat brains than the model group (P < 0.05).


CONCLUSIONS
CQM can ease the mechanical allodynia of photochemically-induced prosopalgia model rats. Its analgesic effect may be related to the decrease of Glu concentrations in striatum extra-cellular fluid.
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China. wyamber@hotmail.com
Ye
Y
Wang
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Dan-Qiao
DQ
Wang
Norman Bethune Medical School, Jilin University, Changchun 130000, China.
Yue
Y
Cui
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Ying
Y
Zhang
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Dan-Dan
DD
Sun
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Xiao-Liang
XL
Zhao
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Yang
Y
Liu
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Mei-Yu
MY
Zhang
Medical Experimental Center, China Academy of Traditional Chinese Medicine, Beijing 100700, China.
Yue
Y
Jiao
Karolinska University Hospital, Stockholm 141 86, Sweden.
Xiao-Jun
XJ
Xu
Life Sciences Institute, Capital Normal University, Beijing 100048, China.
Shi
S
Xu
D000818:Animals; D004365:Drugs, Chinese Herbal / Q000008:administration & dosage*; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010146:Pain / Q000188:drug therapy* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020433:Trigeminal Nerve Diseases / Q000188:drug therapy* / Q000378:metabolism
D004365:Drugs, Chinese Herbal; D018377:Neurotransmitter Agents; D018698:Glutamic Acid