CGRP和NGF对局灶性脑缺血再灌注大鼠海马p53蛋白表达的影响

为了探讨外源性降钙素基因相关肽(CGRP)和神经生长因子(NGF)对局灶性脑缺血再灌注大鼠海马p53蛋白表达的影响,用线栓法制备大鼠大脑中动脉阻塞模型,应用免疫组化和显微图像分析方法检测脑缺血再灌注后大鼠海马CA1区p53蛋白的表达。结果如下:假手术组海马CA1区未见p53阳性细胞,而脑缺血再灌注组阳性细胞明显增多。分别注射CGRP或NGF后海马CA1区p53阳性细胞平均灰度值均明显高于缺血再灌注组(P<0.05),二者联合应用时平均灰度值较单独应用高(P<0.05)。以上结果提示:CGRP和NGF下调缺血神经元p53蛋白的表达,二者合用作用更强,可能对缺血神经元的恢复有促进作用。

THE EFFECTS OF CALCITONIN GENE RELATED PEPTIDE AND NERVE GROWTH FACTOR ON THE EXPRESSION OF p53 PROTEIN DURING FOCAL CEREBRAL ISCHEMIA/REPERFUSION IN RATS

To study the effects of calcitonin gene related peptide (CGRP) and nerve growth factor (NGF) on the expression of p53 protein in hippocampus of rats with focal cerebral ischemia/reperfusion (I/R), middle cerebral artery occlusion (MCAO) was employed to make focal cerebral ischemia, the expression of p53 protein was detected with SABC immunohistochemical method and analyzed by using microimage analysis system. The results showed that the number of p53 protein-positive cells in hippocampus CA1 was obviously increased in focal cerebral I/R group, whereas p53 protein-positive neurons were not observed in sham group. The average gray densities of p53 protein-positive product in CGRP or NGF group were higher compared with I/R group( P<0.05 ). Furthermore, the gray density in CGRP & NGF group was even higher than that in CGRP or NGF group ( P <0.05). The present results indicate that CGRP and NGF downregulate the expression of p53 protein in ischemia neurons and they may cooperate with each other and promote the recovery of the ischemia neurons.