中文摘要：

目的 观察局灶性脑缺血-再灌注大鼠β-连环蛋白（β-catenin）表达的动态变化.方法 取60只SD大鼠,采用改良Zea Longa线栓法栓塞大鼠的大脑中动脉,缺血30 min后再灌注3、6、12、24 h和3、7、14、28 d,按数字法随机分为模型组和假手术组.造模后各时间点每组3只大鼠,对假手术组6只大鼠不栓塞大脑中动脉,其余操作与模型组相同.对两组大鼠进行新鲜取材及用4%多聚甲醛灌注取材,每组3只.采用免疫组化法和免疫印迹法分别检测各组大鼠脑室管膜下区（SVZ）和皮质β-catenin蛋白表达情况.结果 （1）免疫印迹检测大鼠脑梗死侧皮质β-catenin表达与假手术组（0.82±0.01）相比,β-catenin表达从缺血-再灌注后3 h开始升高,12 h时下降至最低点（0.55±0.03）,随后表达上升,在24 h时达到高峰（1.28±0.07）,之后7 d内维持较高水平,但14 d后下降,直至28 d时（0.88±0.02）表达仍高于假手术组.与假手术组比较差异均有统计学意义（P＜0.01）.（2）免疫组化检测大鼠梗死侧SVZ β-catenin的表达从局灶性脑缺血-再灌注后24 h至28 d时,β-catenin阳性细胞光密度值均高于假手术组（86 581±321）,其中在7 d时达到高峰（581 578±29 016）,随后下降.以上各时间点与假手术组的比较,差异均有统计学意义（P〈0.01）.结论 大鼠局灶性脑缺血-再灌注后,大脑皮质和SVZ区的β-catenin表达均随时间呈动态变化.提示可能激活了β-catenin参与的调节神经发生的信号通路.而造模后12 h皮质β-catenin蛋白表达的降低,可能是由于缺血急性期多条信号通路发生了负反馈调节所致.

英文摘要：

Objective To observe the dynamic changes of [3-catenin expression of focal cerebral ischemia-reperfusion in rats. Methods A total of 60 SD rats were selected. Their middle cerebral arteries were occluded by using the modified Zea Longa suture method. After ischemia for 30 min, the rats were reperfused for 3,6,12,24 h and for 3,7,14,28 d. They were randomly divided into either a model group or a sham operation group according to the random number method. After modeling, there were 3 rats in each group at each time point in the sham operation group. The middle cerebral arteries of 6 rats in the sham operation group were not occluded, and other operations were the same with the model group. Fresh and 4% paraformaldehyde samples were obtained in the rats of both groups （n = 3 in each group）. Immu- nohistochemistry and Western blot were used to detect the expression ofβ-catenin proteins in subventricular zone （SVZ） and cortical area in rats of each group. Results （ 1 ） The cortical -catenin expression on cerebral infarction sides was detected by Western blot. Compared with the sham operation group （0.82 ~0.01 ） ,the expression of -catenin began to rise at 3 hours after ischemia-reperfusion, and it dropped to the lowest at 12 hours （0.55 ±0.03） ,and it began to rise and reached the peak at 24 hours （1.28 ± 0.07 ）. Then it maintained a higher level within 7 days, but it decreased after 2 weeks and the expression was still higher than that of the sham operation group until 4 weeks （0. 88 ± 0.02）. There were significant differences （P 〈 0.01 ）. （2）Immunohistochemistry was used to detect the expression of 13-catenin in SVZ on infarcted sides from 24 hours to 28 days after focal cerebral ischemia-reperfusion. The optical density value of ~-catenin positive cells was higher than the sham operation group （86 581±321 ） ,and it reached the peak at day 7 （581 578 ± 29 016）, and then it decreased. The above each time point was compared with the sham operation group using t test.