大鼠脑缺血再灌注后不同时段中枢杏仁核CRF的表达变化

Alterations in Protein Expression of CRF during Reperfusion after Ischemia in the Amygdaloid Nucleus of Rats

目的采用免疫细胞化学技术,探讨脑缺血再灌注后不同时间段大鼠中枢杏仁核促肾上腺皮质激素释放因子(CRF)的表达变化及规律。方法雄性Wistar大鼠70只,随机分成正常对照组、假手术对照组、脑缺血再灌注组,以颈动脉引流法行全脑缺血再灌注造模,术后分6h、24h、72h三个时间段取脑,脑组织恒冷箱连续冠状切片,免疫细胞化学ABC反应,图像分析系统行杏仁中央核群促肾上腺皮质激素释放因子样阳性免疫面积、平均吸光度检测。结果术后6h假手术对照组、脑缺血再灌注组两组CRF阳性免疫面积和平均吸光度值均较正常对照组显著升高(P<0.05),处于表达高峰,然后逐渐回落。72h时假手术对照组CRF表达接近正常值水平(P>0.05),而脑缺血再灌注组仍处于高表达状态(P<0.05)。在三个不同时间段,三组CRF表达变化不一致。术后6h及24h两个时间段,脑缺血再灌注组>假手术对照组>正常对照组;术后72h时间段,脑缺血再灌注组>假手术对照组≥正常对照组。结论在脑缺血再灌注后不同时间段,杏仁中央核群神经元促肾上腺皮质激素释放因子样阳性免疫物表达呈现明显的时间规律;杏仁中央核群促肾上腺皮质激素释放因子能神经元可能在脑缺血再灌注损伤过程中发挥重要作用,脑缺血再灌注早期(6h前后)其促肾上腺皮质激素释放因子的高度表达可能与随后神经元的损伤、丢失密切相关。

Objective： By immunohistochemistry and compute-assisted image analysis, we investigate the changes in protein expression of CRF levels in the amygdaloid nucleus of rat during reperfusion after ischemia. Methods： 70 male wistar rats randomly divided into 3 groups： normal control group （n= 10）, sham-ischemia group（n= 30）, cerebral ischemia-reperfusion group（n=30）. Temporary cerebral ischemia-reperfusion injury model was established by using common carotid artery blood drainage method. Brain section was obtained by cryostat sectioning. The section was prepared for CRF immunohistochemistry staining and was observed by optical microscope. Quantitative analysis was carried out for CRF immunoreactive matter stain area and density. Results： During ischemia reperfusion, the expression of CRF protein in amygdaloid nucleus was increased sharply at 6h, 24h and 72h. Conclusion： The present results demonstrate that the sharply expression of CRF protein in brain at early reperfusion might be one of the mechanism for delayed brain ischemia reperfusion injury.