| BACKROUNDSMigraine is a common and paroxysmal disease with vascular-neurological disfuction.It has become one of chronic diseases which affects the work and life of the patient seriously.Its etiopathogenisis and pathogenesis are not clear,so targets of drug treatment are different.Adenosine 2A receptor is one of the four adenosine receptors,which belongs to G protein-coupled receptor family.It brings about biological effect coupled with different G protein and protein kinase.In the central nervous system,adenosine regulates movement,neuron protection,sleep, awareness,pain,drug addiction,stroke,neurodegenerative disorders and other important pathophysiological process though its receptors.Vasoactive intestinal peptide is a braingut petide,which belongs to glucogan/secretin family.Due to its widespread distribution in peripheral and central nervous system,VIP has many important biological effect,such as regulation of the tension of smooth muscle,regulation of neuroendocrine function,neuron protection.Sebasti(?)o and Cunha found that activation of A2AR enhanced the excitatory action of VIP on GABA release and led to excitatory actions of CGRP on synaptic transmission.Hohoff and his workers assessed the frequency of a six-marker haplotype in migraine patients(n=265)with or without aura(MA/MO),this indicated that A2AR gene variation might contribute to the pathogenesis of migraine with aura.Ledent and his intimates found hypalgesia was existed in adenosine 2A receptor knockout mice.Utill now,there is no report about the pathogenesis of A2AR and VIP in migraine attack.Flunarizine is a prolonged action and nonselective calcium channel blocker.Studies confirm that Flunarizine is a safe and effective medicine,which could decrease the frequency of migraine attack and attenuate the degree of headache with light side effect.In the experiment,firstly,NTG induced migraine model will be built and interfered with Flunarizine.Secondly,the expression of A2AR mRNA and protein or VIP mRNA and the content will be detected in brain stem and trigeminal ganglion.Then the possible relationship between A2AR,VIP and migraine will be investigated,after comparing the changes of the substances during onset and outside of attack.ObjectionsTo make the Nitroglycerin induced experimental migraine model, and to investigate the possible mechanisms of A2AR in the procession of migraine.Methods1.Grouping and treatment:40 Sprague-Dawley(SD)rattus were divided into three randomized groups,which were called model group,NS control group and Flunarizine group.Model group:building migraine model according to Tassorelli's method,NTG was injected subcutaneouly by 10 mg/kg,1 time every week for 5 weeks,this group was were intragastric administration by 10ml/kg everyday for 4 weeks from the second building time by saline.At the same time,Flunarizine group were intragastric administration by 5 mg/kg everyday for 4 weeks from the second building time.2.Materials:onset group and outside group were killed at 3h or 4d after the fifth building respectively,brain stem and trigeminal ganglion were taken out from the rats and stored in liquid nitrogen.3.The expression of mRNA of A2AR and VIP in brain stem and trigeminal ganglion were detected by RT-PCR.4.The expression of protein of A2AR in brain stem and trigeminal ganglion were investigated by Western-Blot.5.The content of VIP in brain stem and trigeminal ganglion were detected by radioimmunuoassy.Results1.the expression of A2AR mRNA and protein of brain stem and trigeminal ganglion in model group and Flunarizine group during attack were more than its control group(P＜0.05);however,during the outside of attack,no statistical differences were observed.2.The content of VIP of brain stem and trigeminal ganglion in model group and Flunarizine group during attack were more than its control group(P＜0.05),however,during the outside of attack, no statistical differences were observed;there were no differences in the expression of VIP mRNA during attack and outside of attack.Conclusions1.The up-regulate of A2AR mRNA and protein and the content of VIP may be possiblely related with migraine attack.2.The effect of Flunarizine in attenuating migraine attacks may be not related with the expression of A2AR,VIP. |
PDF Full Text Request