转化生长因子-β_(1)对成年大鼠视神经夹伤后视网膜节细胞及视神经功能影响的实验研究

Experimental study of influence of transforming growth factor-β_(1) on retinal ganglion cells and optic nerve function after optic nerve crush in adult rats

目的探讨外源性转化生长因子-β_(1)(TGF-β_(1))对成年大鼠视神经夹伤的保护作用。方法雄性SD大鼠25只,随机分为正常未干预组(正常组)、单纯夹伤组(夹伤组)、夹伤联合玻璃体腔生理盐水注射对照组(对照组)、夹伤联合玻璃体腔TGF-β_(1)注射组(实验组)。大鼠麻醉后,眶内段距视神经根部2 mm处显微镊夹伤视神经10 s后立即于玻璃体腔注入5μL TGF-β_(1)或生理盐水,于夹伤第7、14天取材。夹伤视神经前7天,5%荧光金上丘标记视网膜节细胞(RGCs)。分析实验动物的视网膜HE染色、存活RGCs计数和闪光视觉诱发电位(F-VEP)结果,以评估TGF-β_(1)对大鼠视神经夹伤的保护作用。结果视网膜HE染色结果示,夹伤第7、14天,实验组的视网膜的内丛状层厚度均优于对照组(P<0.05)。夹伤第7、14天,实验组的荧光金标记RGCs密度较对照组明显增加(P<0.05)。夹伤第14天,实验组与对照组的P1波潜伏期比较,差异具有统计学意义(P<0.05)。结论TGF-β_(1)在视神经夹伤后可维持视网膜结构,保护RGCs的存活,并改善F-VEP中P1波潜伏期。

Objective To investigate the protective effect of exogenous transforming growth factor-β_(1)(TGF-β_(1))on optic nerve crush in adult rats.Methods Twenty-five male SD rats were randomly divided into normal non-intervention group(normal group),simple crush group(pinch injury group),crush combined with intravitreal normal saline injection control group(control group),crush combined with intravitreal TGF-β_(1) injection group(experimental group).After anesthesia,5μL TGF-β_(1) or normal saline was injected into the vitreous cavity immediately after the optic nerve was crush by micro tweezers 2 mm away from the root of the optic nerve for 10 s.The samples were taken on the 7th and 14th days of crush.Retinal ganglion cells(RGCs)were labeled with 5%fluorescent gold in the superior colliculus on 7 d before optic nerve crush.The results of retinal HE staining,survival RGCs count and flash visual evoked potential(F-VEP)of experimental animals were analyzed to evaluate the protective effect of TGF-β_(1) on optic nerve crush in rats.Results The retinal HE staining result showed that the thickness of inner plexiform layer of retina in the experimental group were better than those in the control group on the 7th and 14th days of crush(P<0.05).On the 7th and 14th days of crush,the density of fluorescent gold labeled RGCs in the experimental group was significantly higher than that in the control group(P<0.05).On the 14th day of crush,there was significant difference in P1 wave latency between the experimental group and the control group(P<0.05).Conclusion TGF-β_(1) can maintain the retinal structure,protect the survival of RGCs,and improve the P1 wave latency in F-VEP after optic nerve crush.