复合神经营养因子对大鼠视神经损伤后轴突数的影响

The effect of neurotrophins optic nerve fibers(CNTF and BDNF) in treatment to rats with optic nerve lesion

目的观察玻璃体腔注射复合神经营养因子[睫状神经营养因子（CNTF）＋脑源性神经营养因子（BDNF）]对大鼠视神经损伤后轴突的形态和纤维数目变化的作用。方法60只雌性健康成年SD大鼠、体重200-225 g,随机分为对照组、CNTF治疗组、BDNF治疗组及复合神经营养因子（CNTF＋BDNF）治疗组。各组又分为7、14、21 d 3个时间组,每组5只大鼠,每只动物进行单眼实验,另外一眼为正常对照。四组制成视神经损伤模型后分别向玻璃体腔内注射生理盐水、CNTF、BDNF、CNTF＋BDNF。按视神经损伤后不同时间点,分别将动物灌注固定。完整取下视神经,固定,包埋,切片处理后进行图像分析,对正常大鼠视神经内的轴突数和夹伤后大鼠视神经内的轴突数的变化规律进行观察和分析。结果视神经轴突计数结果显示各组轴突数随时间推移逐渐减少。与对照组相比CNTF治疗组、BDNF治疗组及CNTF＋BDNF治疗组7、14、21 d各组轴突数均明显多于对照组（P〈0.01）,且CNTF＋BDNF治疗组轴突数亦明显多于单独应用CNTF治疗组、BDNF治疗组（P〈0.01）。结论在对大鼠视神经损伤的治疗中,应用CNTF＋BDNF明显优于单独应用CNTF或BDNF。

Objective To investigate in vivo the survival of optic nerve fibers after optic nerve was crushed with vitreous cavity injection of neurotrophins （BDNF and CNTF）. Methods Sixty Sprague-Dawly （SD） healthy female rats were randomly divided into 4 groups： control group, BDNF group, CNTF group and neurotrophins （BDNF and CNTF） group. Each group is also divided into three time groups： 7 day, 14 day, 21 day, each group of which contains 5 rats with right eye to be tested and left eye to be normal control. The optic nerve was intraorbitally crushed and each group was injected different medicine to vitreous cavity in such an order： NaCl （0.9%）, CNTF, BDNF, and neurotrophins （CNTF and BDNF）. According to different time point, the optic nerve crush rats were perfused. We extract the whole optic nerve, dispose with electronic microscope and use a computerized image analysis system from which we research varying rule of number of optic nerve fibers with optic nerve lesion. Results After optic nerve was crushed, each group＇s densities of optic nerve fibers decrease with time lapse. The number of optic nerve fibers in the three treatment groups, BDNF group, CNTF group and neurotrophins （BDNF and CNTF）group, are obviously more than that of control group at the points of 7 day, 14 day and 21 day （P〈 0.01 ）. The number of optic nerve fibers in neurotrophins （BDNF and CNTF） group is also more than that of BDNF group and CNTF group which only use one kind of neurotrophic factors （P〈 0.01 ）. Conclusion In the treatment of rats with optic nerve lesion, using neurotrophins （BDNF and CNTF） is superior than using one neurotrophic factors （CNTF or BDNF）alone.