[Effect of electroacupuncture on cortical spreading depression and plasma CGRP and substance P contents in migraine rats].
OBJECTIVE
To observe the effect of electroacupuncture (EA) on cortical spreading depression (CSD) and contents of plasma calcitonin gene-related peptide (CGRP) and substance P (SP) in migraine rats.


METHODS
Thirty male SD rats were equally randomized into control, model and EA groups. Migraine model was established by topical application of KCI (3 mol/L) immersed in a piece of filter paper to the cerebral cortex (parietal lobe, 6 mm posterior to the Bregma and 5 mm to the sagital fissure) after exposure of the skull (in reference to Michael' method). KCI stimulation evoked CSD potentials (3 mm rostral to the Bregma, and 2 mm to the sagital fissure) were recorded by using a glass microelectrode. For rats of control group, filter paper containing 0.9% NaCl was applied to the same parietal cortex area. EA (1 mA, 2 Hz/100 Hz) was applied to bilateral "Yanglingquan" (GB 34) and "Taichong" (LR 3) for 30 min. The contents of plasma CGRP and SP were assayed by radioimmunoassay.


RESULTS
CSD was induced 3-5 min after application of KCI to the parietal lobe. The average amplitude of model group was (-25.13 +/- 1.23) mV, and that of EA group was (-19.19 +/- 1.53) mV, displaying a significant reduction of CSD amplitude after EA (P < 0.01). Comparison among 3 groups showed that both plasma CGRP and SP contents in model group were significantly higher than those of control group (P < 0.001, P < 0.01), while compared with model group, plasma CGRP and SP levels in EA group decreased considerably (P < 0.05, P < 0.001), suggesting an inhibitory effect of EA on pain-producing substance.


CONCLUSIONS
EA of GB 34 and LR 3 can effectively suppress KCI provoked cortical spreading depression and plasma CGRP and SP levels in the rat, which may contribute to its effect in relieving migraine in clinic.
Shi
Hong
H
Institute of Acu-mo.ribustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Li
Jiang-hui
JH
Ji
Chang-fu
CF
Shang
Hong-yan
HY
Qiu
En-chao
EC
Wang
Jing-jing
JJ
Jing
Xiang-hong
XH
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000097:blood*; D013181:Cortical Spreading Depression; D004195:Disease Models, Animal; D015671:Electroacupuncture; D006801:Humans; D008297:Male; D008881:Migraine Disorders / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000097:blood*
D013373:Substance P; D015740:Calcitonin Gene-Related Peptide