慢性脑缺血大鼠脑内胰岛素样生长因子-1和Nogo-A的表达

Expression of Nogo-A and IGF-1 in brain tissue of chronic cerebral hypoperfusion rats

目的:研究大鼠慢性脑缺血后大脑皮层和海马中Nogo-A和胰岛素样生长因子-1(IGF-1)的表达及意义。方法:40只Wistar大鼠随机等分为假手术对照组和模型组,模型组结扎双侧颈总动脉建立慢性脑缺血模型。缺血3个月后采用免疫组织化学SP法在光镜下观察2组大鼠大脑皮层和海马IGF-1和Nogo-A的表达。结果:对照组皮层和海马偶有神经元变性、死亡;正常神经元数目较多。模型组皮层和海马有大量神经元变性、死亡;正常神经元数目较少。模型组皮质和海马IGF-1表达与对照组比较,差异无统计学意义(t=-0.254,-1.890,P>0.05)。模型组皮质和海马Nogo-A表达高于对照组(t=-13.463,-13.133,P<0.05)。结论:慢性脑缺血后抑制神经再生的因子Nogo-A表达增强,这可能是成年哺乳动物损伤后神经再生障碍的重要原因之一。

Aim： To explore the dynamic changes of IGF-1 and Nogo-A expressions in cortex and hippocampus of chronic cerebral hypoperfusion rats. Methods ： A total of 40 Wistar rats were distributed to control group and model group randomly and equally. Chronic cerebral ischemie rat model was established by permanent occlusion and snip of bilateral common carotid arteries. Three months after the operation, the expressions of Nogo-A and IGF-1 in rat＇ s brain cortex and hippoeampus were determined using immunohistochemical technique. Results： Only a few degenerated and dead neurons were found in cortex and hippocampus,while most neurons were normal in control group. A lot of degenerated and dead neurons were found in model group,and normal neurons were less. The expression of IGF-1 in cortex and hippoeampus in model group were not different from those of the control group（ t = - 0. 254, - 1. 890,P 〉 0. 05 ）. The expression of Nogo-A in cortex and hippocampus in model group were higher than those of the control group（ t = - 13. 463, - 13. 133 ,P 〈 0.05 ）. Conclusion： The over-expression of Nogo-A after chronic cerebral ischemie may play an important role in the nerve regeneration in rats.