Exploration On Application Of The Neuropeptides CGRP, SP And Receptor Neurokinin-1 To Explain The Mechanism Of Electroacupuncture For Acute Migraine In Rats

Objective:A migraine is a common nervous system disorder manifested as recurrent attacks of a unilateral or bilateral temporal headache.And it is often accompanied by nausea,vomiting and so on.Acupuncture is effective and working remarkably well for treatment headache and reducing the paroxysmal frequency for the migraines.However,The pathogenesis of migraine is not fully understood as yet.With the development of modern social medicine,more and more authors review experimental researches on the mechanism of migraine gradually into the neuropeptide levels.The study found that a variety of the pain of neuropeptides is closely related to migraine.Such as neuropeptides family SP and its receptor NK-1,Calcitonin generelated peptide(CGRP)and 5-hydroxytryptamine(5-HT),nitric oxide(NO),endothelin,etc.substance P and calcitonin related peptide(CGRP)as neurotransmitters play an important role in the sensory conduction and pain modulation.And the researchers pay more and more attention to it.A large number of experiment has proved the neuropeptides SP and CGRP in neural modulation can transmit pain information,and can promote the enkephalin(ENK)release,in order to achieve the analgesic action.So by copying subcutaneous injection of nitroglycerin migraine rats models in this experiment.The purpose of this study is to observe the effect of electroacupuncture(EA)on the expression of substance P(SP)and its receptor Neurokinin-1 in the Mesencephalon and plasma concentrations of CGRP in rats with acute migraine.Methods:The 80 adult healthy male Wistar rats,its weight between 250 to 350 g with clean laboratory feeding,feeding freely and drinking water.Raising temperature(22 ±1? C),humidity are between 40% ~ 70%,the noise < 60 decibels,ventilation rate 10 ~ 20 times/min,illumination time 12 hours a day(8:00~20:00).rats were equally randomized into 4 groups: control(group A),model(group B),electroacupuncture(group C),Non-electroacupuncture(group D).In group A,rats were normal feed for 7 days and injected with isotonic saline at 8 dyas.In group B,rats were regularly feed and injected subcutaneously with 10 mg/ kg nitroglycerin to set up the model of migraine without electroacupuncture treatment.The groups C and D were treated by EA for seven days,the group C chooses the acupoints of taiyang(EXHN5),Fengchi(GB 20),Taichong(LR 3),Zulinqi(GB 41).and the group D was treated with the points of Non-acupoints.After that using nitroglycerin method replicating experimental rat model with migraine,using EA treating these rats after modeled for 15 ~ 30 min.The expression of CGRP was detected by using enzyme-linked immunosorbent assay(ELISA),SP and receptor Neurokinin-1(NK-1)were analyzed by using immunohistochemical staining and Reverse transcription-polymerase chain reaction(RT-PCR).Results:1.Acupuncture on acute migraine rats the influence of the concentration of plasma CGRP,the level of CGRP in compared with model group(group B)and Non-acupoint(group D),the electroacupuncture group(group C),control group(group A)significantly decreased(P<0.05).No statistically significant differences(p>0.05)were found between groups A and C,B and D(P>0.05).2.Acupuncture on acute migraine rats the influence of gene expression of SP and NK-1,The results showed that The expression of SP and NK-1 mRNA increased in groups B,C and D compared with the group A(P<0.05),the group C,D was significantly lower than group B(P<0.05).compared with group D,the SP and NK-1 mRNA of group C obviously decreased in brain of rats.3.the quantity and distribution of SP and NK-1 expression on The periaqueductal gray(PAG)area in acute migraine rats by Acupuncture treated.Experiments have shown the change of Positive cells number of SP.Group B and D was higher than group A and C(P<0.05).No statistically significant differences(p>0.05)were found in Group A and group C,group B and group D.The expression of NK-1 increased in groups B,C and D compared with the group A(P<0.05),but there all were no statistical difference between group B and C and D(P >0.05).Conclusion:Electroacupuncture can efficiently prevent and treat acute migraine in the rats by down-regulating expression level of neuropeptides CGRP and SP.