改构体和野生型aFGF对大鼠视神经夹挫伤后的保护作用

Protective effect of modified and wild type acidic fibroblast growth factor after rat optic nerve crush

目的观察改构体酸性成纤维细胞生长因子(MaFGF)和野生型酸性成纤维细胞生长因子(aFGF)对视神经夹挫伤后的保护作用。方法健康Wistar大鼠42只随机分为7组:生理盐水组,aFGF0.25、1.0、4.0μg/mL组,MaFGF0.25、1.0、4.0μg/mL组。均制成右眼视神经夹挫伤模型,于伤后1h及4周分别记录左右眼的闪光视觉诱发电位(F-VEP),分5次向右眼球后注入各组液体0.1mL。取眼球及部分视神经,光镜下观察形态学改变,计数视网膜神经节细胞(RGCs)。结果伤后1h,MaFGF和aFGF各组F-VEP潜伏期均延长,波幅均降低,与正常对照组相比差异均有统计学意义(P<0.01)。伤后4周,较生理盐水组F-VEP更接近正常值(P<0.05),RGCs计数均明显增多(P<0.01)。结论MaFGF和aFGF对轴索的退变和RGCs有明显的保护作用,且这种保护作用不依赖于其有丝分裂活性。

Objective Acidic fibroblast growth factor can promote wound healing,protect nerve and improve local ischemia. This study was to observe the protective effect of modified and wild type of acidic fibroblast growth factor （aFGF） on optic nerve crush and study the degree of nerve protective effect bank of aFGF to mitosis activity. Methods Forty-two Wistar rats were divided into 7 groups randomly, or normal saline solution group,0. 25,1.0,4. 0 t^g/mL aFGF groups and 0. 25,1.0,4. 0 μg/mL MaFGF groups. The optic nerves of the right eyes of rats were crushed by special nip, and the left eyes were as normal controls. Flash visual evoked potentials（F-VEP） of rats was recorded at 1 hour and 4 weeks after crushing of optic nerve. 0. 1 mL aFGF or MaFGF was retrobulbarly injected in the right eyes on the 3 rd ,5 th,7 th and 9 th day after injury. The eyeballs and optic nerve of rats were enucleated for histological examination under the microscope and retinal ganglion cells（RGCs） were counted. Results One hour after crush,the latency period of F-VEP was significantly extended and the amplitude were depressed, showing distinct difference from normal F-VEP（ P 〈 0. 01 ）. Four weeks later, F-VEP approached normal level in MaFGF and aFGF group, showing a statistical difference in comparison with normal saline solution group（ P 〈 0. 05 ）. The numbers of RGCs were enhanced in various groups of MaFGF and aFGF compared with normal saline group（ P 〈 0. 01 ）. No significant differences were found among MaFGF and aFGF groups in F-VEP and RGCs counting（P 〉 0. 05 ）. In normal saline solution group, the number of optic nerve myelin sheath was statistically lower than that of normal and typical vacuole was seen. In various groups of MaFGF and aFGF, these changes still existed,but the number of myelin sheath was enhanced than normal sailing solution group. Conclusion MaFGF and aFGF can abate the change of F-VEP and increase the living number of RGCs after optic nerve crush in rats. A protective effect of MaFGF and aFGF to secondary degeneration of RGCs is determined,and this effect dose not depend on cellular mitosis activity.