耳缘静脉放血对偏头痛家兔模型的镇痛效应及中脑导水管周围灰质c-fos表达的影响

目的观察耳缘静脉放血对偏头痛家兔模型的镇痛效应及对中脑导水管周围灰质（PAG）c-fos的表达,从而揭示耳缘静脉放血的镇痛作用机制。方法 30只新西兰家兔按随机数字表分为耳缘静脉放血组、模型组和空白组。按5 mg/kg标准连续3 d颈后皮下注射硝酸甘油复制偏头痛家兔模型,在第3天造模60 min后耳缘静脉放血,分别在造模前、造模30 min和放血后即刻进行痛阈测定。免疫组化法观察偏头痛家兔模型PAG区c-fos表达。结果痛阈改变：造模30 min耳缘静脉放血组和模型组的痛阈明显降低,与造模前比较有统计学意义（P〈0.01）,与空白组比较均有统计学意义（P〈0.01）;耳缘静脉放血组放血后即刻痛阈明显升高,与造模30 min比较有统计学意义（P〈0.01）,与模型组比较有统计学意义（P〈0.05）;耳缘静脉放血组家兔模型PAG区c-fos阳性细胞数明显降低,与模型组比较有统计学意义（P〈0.01）。结论耳缘静脉放血有明显的镇痛作用,通过抑制偏头痛家兔模型PAG区c-fos基因表达发挥了镇痛效应。

C-fos expression in PAG area of ear-edge vein bloodletting on rabbit models of migraine

Objective To observe the analgesic effect of ear-edge vein bloodletting on rabbit and the influence of c-fos ex- pression in the periaqueductal gray （PAG） area. Consequently, reveal the analgesic mechanism of marginal vein bloodletting ears. Methods 30 New Zealand rabbits were randomly divided into 3 groups, ear-edge vein bloodletting group, model group and blank group. By subcutaneous injection nitroglycerin in the rabbits＇ neck according to the standard of 5 mg/kg for 3 day, the migraine models were successfully copied. The ear-edge vein blood were ensanguined after 60 minutes of molding, pain threshold was determined in front of the building, building immediately after 30 min and bleed. Then we observed the expression of c-fos in PAG of rabbits by immunohistochemical method after the end of the course. Results The change of pain threshold： the pain threshold of ear-edge vein bloodletting group and model group were significantly reduced, compared with before building has a very significant difference （ P 〈 0.01 ）, and compared with blank group has a very significant dif-ference （P 〈 0.01 ） ;the immediate pain threshold of ear-edge vein bloodletting group was increased significantly, compared with after 30 minutes of molding has a very significant difference （ P 〈 0.01 ）, and compared with model group has a very significant difference （ P 〈 0.01 ） ; positive ceils in the PAG area c-los of ear-edge vein bloodletting group were significantly decreased, compared with model group （ P 〈 0.01 ）. Conclusion The therapy of ear-edge vein bloodletting has analgesic effect, which can decrease the expression of c-fos gene in PAG of rabbit models of migraine.