The Effect Of1-methyl Tryptophan On The C-fos Protein Expression Which Is Induced By Nitroglycerin In The Brainstem Of Model Rats Of Migraine

ObjectiveThrough giveing the indoleamine2,3-dioxygenase (IDO) competitive inhibitor1-methyl tryptophan(1-MT) preventative to Sprague Dawley (SD) rats, appraiseing ethological changes of nitroglycerin induced hyperalgesia in model rats of migraine and the impact of the c-Fos protein expression in the TNC, to inquire into the effect of IDO inhibitor on the migraine attcack and its possible mechanism.Methods1. Grouping and building model:30SD rats weighted200～250g were randomly divided into two groups, False model group and Model group. Model group:according to Tassorelli, NTG was injected subcutaneouly by10mg/kg, to make experimental migraine model. Turning red of ears and frequency of scratching head and climbing hutch were considered to be successful sign for making experimental migraine mode. The rats making migraine mode successfully were called model group. The three rats making migraine mode unsuccessfully were classified into the blank group. The rats of model group were divided into model control group and treatment group.False model group:NS was given by intragastric administration by2ml/kg/d for seven times. NS was injected subcutaneouly by2ml after the7th time.Model control group:NS was given by intragastric administration by2ml/kg/d for seven times. NTG was injected subcutaneouly by2ml after the7th time.Treatment group:1-methyl tryptophan(l-MT) was given by intragastric administration by100mg/kg/d for seven times. NTG was injected subcutaneouly by2ml after the7th time.2. To appraise behavior changes of the rats respectively after NTG was inject subcutaneously. The time of turning red of ears and frequency of scratching head and climbing hutch were observed every30minuts after infusion and comparae with eachother.3.4h after NTG was injected subcutaneously for the2th time, rats were paral and perfuse to fix, which the brainstem were removed and post-fixed. The expres of c-Fos immuno-reactivities was detected with immunehistochemical method Results:1. Ethology comparison:Three rats is unsuccessful to make experiment models. About4minutes after modeling, the rest of rats appeared some special behavior and symptom, such as red ears, scratching head and climbing hutch. The blank control group appear scratching head and climbing hutch for a short duration. The1-methyl tryptophan was effective in relieving the behavior and symptom of nitroglycerin induced hyperalgesia in model rats of migraine (p<0.05)2. Expression of the c-Fos protein:In microscope, the cell was tasteless in back ground, the positive cell was yellow in TNC. The positive cell in model group was obviously increased compared with blank group (p<0.05); The positive cell in treatment group was also increased, but there was a significantly reduced compared with model group (p<0.05)Conclusion:1-Methyl tryptophan is effective in relieving the behavior and symptom of nitroglycerin induced hyperalgesia in model rats of migraine, and able to reduce the c-Fos expression induced by nitroglycerin. This shows that inhibit the activity of IDO may be have a preventive effect for migraine attacks. The results further proved that kynurenine metabolic pathways may be associated with the pathogenesis of migraine and treament, and also will provide a new strategy for the prevention of migraine attacks...