应用液压冲击颅脑损伤仪建立大鼠外伤性视神经损伤动物模型

目的 观察应用液压冲击颅脑损伤仪(FPI)能否成功建立大鼠外伤性视神经损伤动物模型.方法 成年雌性Wister大鼠71只,随机选取5只为正常对照组,其余66只为模型组.模型组再随机分为3组.第1组8只大鼠,分别于损伤前、损伤后1、3 d、1、2、4、6、8周行双眼闪光视觉诱发电位(F-VEP)及视神经核磁共振成像(MRI)检查;第2组56只大鼠,随机分成7个亚组,每个亚组8只大鼠,分别于损伤后1、3 d、1、2、4、6、8周行视网膜组织病理学及末端脱氧核苷酸移换酶介导的dUTP缺口末端标记测定法(TUNEL)检测;第3组2只大鼠,分别于损伤后4、8周行视神经透射电子显微镜检测.根据打击力量不同.将损伤眼分为轻、重2组.重伤组打击锤以25.的预定角度打击视神经,平均打击力量(699.14±60.79)kPa,轻伤组以15°的预定角度打击,平均打击力量(243.18±20.26)kPa.每只大鼠右眼为重伤组,左眼为轻伤组.结果 重伤组损伤后1d主波潜伏期延长,与正常对照组比较,差异有统计学意义(t=2.06,P<0.05);F-VEP振幅在损伤后2周内逐渐降低,2周后趋于稳定(F=1.98,P>0.05).轻伤组损伤后1 d主波潜伏期延长,与正常对照组比较,差异有统计学意义(t=2.19,P<0.05);振幅在损伤后4周内逐渐降低,4周后趋于稳定(F=1.62,P>0.05).MRI检查显示,损伤后1 d视神经高信号,损伤后8周仍较明显.组织病理学检查发现,损伤后1 d视网膜神经节细胞层(GCL)可见毛细血管破裂出血;损伤后4周GCL内可见空化的视网膜神经节细胞.损伤后3 d视网膜各层均出现凋亡阳性细胞;TUNEL染色发现损伤后1、2周凋亡阳性细胞明显增多.结论 应用FPI能成功建立大鼠外伤性视神经损伤模型.

Optic nerve injury model in rats set up by fluid percussion brain injury device

Objective To observe whether the animal model of optic nerve injury in rats can be set up by fluid percussion brain injury device (FPI) or not.Methods Seventy-one healthy female Wister rats were randomly divided into 2 groups,inlcuding model group with 66 rats and control group with 5 rats.The rats in model group were randomly divided into 3 groups.Eight rats in group 1 were examined by flash-visual evoked potential (F-VEP) and magnetic resonance imaging (MRI) examines before and 1,3 days,1,2,4,6,and 8 weeks after injury;56 rats in group 2 were randomly divided into 7 subgroups with 8 rats in each subgroup,and were detected by histopathologieal and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) apoptosis examines 1,3 days,1,2,4,6,8 weeks after injury;2 rats in group 3 were examined by electron microscopy 4 and 8 weeks aher injury.According to the degree of injury,the injured eyes were divided into 2 groups including severe injury group with the beat pressure of (699.14±60.79) kPa and mild injury group with the beat pressure of (243.18±20.26) kPa.The right and left eyes in rats in each group were in severe and mild injury group,respectively.Results One day after injury,the latency duration of F-VEP prolonged in severe injury group,wich differed much form which in the normal control group (P<0.05);the amplitude was gradually reduced during the first 2 weeks after injury and kept steady after that (P>0.05).The latency duration prolonged in mild injury group,and its difference with the normal control group was statistically significant (P<0.05);the amplitude was gradually reduced during the first 4 weeks after injury and kept steady after that (P>0.05).The abnormal high signal could be seen on optic nerve 1 day after injury,and was still obvious 8 weeks later.The results of histopathological examination showed ruptured capillary in ganglion cell layer 1 day after injury;retinal ganglion ceils without nucleus could be seen 4 weeks after injury.The apoptosis of positive cells was found in each layer of the retina 3 days after injury.TUNEL results indicated that the number of apoptotic positive cells increased significantly 1-2 weeks after injury.Conclusion An animal model of optic nerve injury can be successfully set up using FPI in rats.