The Neroprotection Of BDNF After Retina Reattachment In Retina In The Experiment Of Retinal Detachment

【Objective】To establish animal model of experimental retinal detachment through injectinghealon into the sub-retinal space and to investigate the effect of BDNF on the retinalrepair after RD reattached from the apoptosis of photoreceptor cells, the morphologyof retina and the ultrastructure of retinal cells by injecting BDNF into Vitreous cavityafter the retina reattached，which provide a theoretical basis for using neurotrophicfactor to suppress the apoptosis of retinal cells after retina reattached and to promotethe recovery of retinal function.【Method】1.Fifty-six normal rats without oculopathy were established animal model ofexperimental rentinal detachment through injectting healon into the subretinal space.The automatical reattachment time of retina was observed.2. Completely randomdesign was applied,.Fifty-six normal rats without oculopathy were divided into4groups,normal control group, BDNF experimental group, NS experimental control group and reattached control group. the BDNF experimental group and NSexperimental control group were injected BDNF （20μg/ml）10μl and NS10μl intovetreous cavity on the day that the retina reattached.3. Take the eyeballs on one week after intravitreal injection to observe themorphology of retina and the ultrastructure of retinal cells by light micoscopy andelectron microscopy and detect the effect of BDNF on retinal degeneration caused byRD.Eye tissue slices were done in order to detect the effect of BDNF on the apoptosisof retinal cells after RD reattached by Terminal deoxynucleotidy transferase mediateddUTPnick end labeling (TUNEL) technique.【results】1. The average automatically reattached time is31.3±3.5days.2. Lightmicoscopy:compared with normal control group, in reattached controlgroup,the oral reattached reina,the inner nuclearlayer of retina (INL), the outernuclearlayer of retina(ONL) and the outer plexiform layer is morethinner.especially in the outer nuclearlayer of retina photorecepters disorderedand the number decreased. Ganglion cell is fewer and nerve fiber layer isthinner.Through statististical analysis,the thickness of ONL and INL in BDNFexperimental group were different from NS experimental control group(P＜0.05);reattached control group was significantly different in comparison to the normalcontrol group(P＜0.05).3. electron microscopy: compared with experimental control group, BDNFexperimental group has more photorecepter cells,thicker outer nuclear layer andless damage.the organizational structure of reina is much better.the degeneration of photorecepter cell inner segment and outer segment is lighter.4. TUNEL:In addition to the normal control group,TUNEL-positive cells can beobversed in the BDNF experimental group, NS experimental control group andreattached control group,mainly in the ONL and INL,photorecepter cell layer alsocan be found. The numbers of TUNEL-positive cells in experimental controlgroup and reattached control group can be clearly counted.In the BDNFexperimental group,there were less TUNEL-positive cells compared withexperimental control group.【Conclusion】1.The retinal morphology and ultrastructure of retinal cells have changed after RDreattached.2.The apoptosis of retinal photoreceptor cells are present in the retina after RDreattached.3.Exogenous BDNF can inhibit the apoptosis of retinal cells and have a certainprotection for the retinal damage caused by RD,which provide a theoretical basis forusing neurotrophic factor to suppress the apoptosis of retinal cells after retinareattached and to promote the recovery of retinal function.