摘要
Background Glaucoma,an irreversible optic nerve neuropathy,always results in blindness.This study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization (EVC) model by multiple in vivo and in vitro evidences.Methods Wistar rat was used in this study.The elevated intraocular pressure (IOP) was induced by cauterization of three episcleral veins.lOP was monitored with Tono-Pen XL tonometer.Time-dependent changes to the neuronal retinal layers were quantified by Fourier domain-optical coherence tomography.The function of retina was evaluated by electroretinogram (ERG).Survival of retinal ganglion cells (RGCs) was quantified by retrograde labeling.Histology study was performed with retinal sections stained with hematoxylin-eosin,glial fibrillary acidic protein,and neuronal nuclear antigen.Retina and aqueous humor protein were extracted and cytotoxic protein tumor necrosis factor alpha (TNF-α) and alpha-2 macroglobulin (α2m) were measured with Western blotting.Results EVC is a relatively facile intervention,with low failure rates (<5%).After surgical intervention,chronic mild lOP elevation (about 1.6-fold over normal,P <0.05) was induced for at least 6 weeks without requiring a second intervention.High lOP causes chronic and progressive loss of RGCs (averaging about 4% per week),progressive thinning of neuronal retinal layers (3-5 μm per week),and reduction of a-and b-wave in ERG.EVC method can also induce glial cell activation and alterations of inflammation proteins,such as TNF-α and α2m.Conclusion EVC method can establish a robust,reliable,economic and highly reproducible glaucomatous animal model.
Background Glaucoma,an irreversible optic nerve neuropathy,always results in blindness.This study aimed to evaluate glaucoma-like features in the rat episcleral vein cauterization (EVC) model by multiple in vivo and in vitro evidences.Methods Wistar rat was used in this study.The elevated intraocular pressure (IOP) was induced by cauterization of three episcleral veins.lOP was monitored with Tono-Pen XL tonometer.Time-dependent changes to the neuronal retinal layers were quantified by Fourier domain-optical coherence tomography.The function of retina was evaluated by electroretinogram (ERG).Survival of retinal ganglion cells (RGCs) was quantified by retrograde labeling.Histology study was performed with retinal sections stained with hematoxylin-eosin,glial fibrillary acidic protein,and neuronal nuclear antigen.Retina and aqueous humor protein were extracted and cytotoxic protein tumor necrosis factor alpha (TNF-α) and alpha-2 macroglobulin (α2m) were measured with Western blotting.Results EVC is a relatively facile intervention,with low failure rates (<5%).After surgical intervention,chronic mild lOP elevation (about 1.6-fold over normal,P <0.05) was induced for at least 6 weeks without requiring a second intervention.High lOP causes chronic and progressive loss of RGCs (averaging about 4% per week),progressive thinning of neuronal retinal layers (3-5 μm per week),and reduction of a-and b-wave in ERG.EVC method can also induce glial cell activation and alterations of inflammation proteins,such as TNF-α and α2m.Conclusion EVC method can establish a robust,reliable,economic and highly reproducible glaucomatous animal model.
基金
This work was supported by grants from Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2010), Key Project of Guangdong Province Natural Science Foundation (No. 10251008901000028).