新西兰兔视神经损伤减压术后视网膜及视神经GAP-43 mRNA的表达及意义

Expression and significance of GAP - 43 mRNA in the optic nerve and retina after optic - nerve decompression in New Zealand rabbits

目的:通过观察视神经损伤后,不同时段手术减压对视神经及视网膜GAP-43mRNA表达的影响,探讨视神经损伤后减压的手术时机及作用机理。方法:定量致伤条件下建立新西兰兔双侧视神经部分损伤的动物模型。根据预定减压时间的不同,将20只新西兰兔随机分为正常对照组、损伤后1d减压组(1dpi组)、损伤后7d减压组(7dpi组)和损伤后14d减压组(14dpi组)4组。以右眼为减压眼,左眼不减压作为损伤对照。利用RT-PCR法检测各组损伤后4周时视神经及视网膜组织中GAP-43mRNA的表达水平。结果:视神经开始损伤后4周时,1dpi组减压眼视网膜组织中GAP-43mRNA的表达高于未减压眼,7dpi组、14dpi组减压眼与未减压眼表达差异无统计学意义。结论:视神经损伤后早期减压可使视网膜GAP-43mRNA表达升高,可能对促进视神经轴突的修复起一定的作用。

Objective ： To study the regularity and functional mechaisms of the expression of GAP - 43 mRNA following optic nerve decompression after partial optic nerve injury, and the molecular mechanism of action of the optic nerve decompression in the nerve recovery, and to determine the location of growth - associated protein 43 messenger ribonucleic acid in the optic nerve and retina after optic - nerve decompression. Methods： New Zealand rabbits were used to ereate animal models of hibateral partial optic nerve injury with the same injury intensity. According to the expected time for decompression, 20 rabbits were divided randomly into normal control, 1 - , 7 - , and 14 - day post - injury groups. The right eye was the decompressive eye contrast to the left undecompressive eye. The animals were sacrificed four weeks after injury. The expressions of GAP- 43 mRNA in optic nerve and retina were explored by reverse transcriptive polymerase chain reaction （RT- PCR）. Results： The expression of GAP-43 mRNA in retina of the decompressive eyes was higher than that of the undecompressive eyes in 1 day post - injury group , but was similar to that of the undecompressive eyes in 7 and 14 days post- injury groups. Conclusion： The decompression of optic nerve in the earlier period after injury can elevate the expression of GAP - 43 mRNA which may promote the process of neurite regeneration.