大鼠外伤性视神经病变后GAP-43表达的变化

The changes of GAP-43 in rats with traumatic optic neuropathy

目的研究大鼠视神经夹挫伤后视神经和视网膜神经节细胞(retinal gangliocytes,RGCs)形态学及生长相关蛋白-43(growth associated protein-43,GAP-43)表达的变化。方法采用大鼠球后视神经钳夹伤模型,分别于损伤后1、4、7、14、28 d处死动物,HE染色观察视神经组织及RGCs的动态改变,免疫组化方法检测视神经轴突GAP-43的表达变化。结果视神经损伤后,RGCs数目明显下降,14 d内降低速度较快,14 d后下降速度减慢;与正常大鼠视神经轴突相比,GAP-43表达明显增加,伤后14 d达峰值,14 d后逐渐下降(P<0.05)。结论视神经损伤后RGCs数量减少是其视功能下降的病理基础之一,视神经轴突GAP-43表达增加是视神经损伤修复的一种表现。

Objective To observe the changes in morphology of optic nerve and retinal gangliocytes （RGCs） as well as the expression levels of growth associated protein-43 （GAP-43） in rats with optic nerve contusion. Methods Intraorbital optic nerve contusion models in rats were established, and the animals were executed at. 1,4,7,14 and 28 days after injury. The morphological changes in optic nerve tissue and RGCs were observed through HE staining. The expression levels of GAP-43 in optic nerve axons were detected by immunohistochemistry. Results The number of RGCs was reduced significantly ＇after optic nerve injury,and the speed of reduction was quicker within 14 days. As compared with those in normal optic nerve axon, the expression levels of GAP-43 were significantly increased in injury group,which peaked at 14 days after injury and gradually decreased afterlg days. Conclusion The decrease of RGCs number after optic nerve injury is one of the pathological mechanisms of visual function lesion. The increase of GAP-43 expression in the optic nerve axons is a kind of injury repairing phenomenon.