Purpose To investigate whether experimental autoimmune uveitis can be induced equally in different rats by urea soluble fraction of bovine melanin-associated antigen(USF-BMAA),and,if so,difference among them. Methods Lewis rats,F344 rats,Wistar rats were immunized with USF-BMAA emulsified with complete Freud is adijuvant and Bordelella pertussis to induce experimental autoimmune uveitis.The animal models were investigated clinically and histopathologically and compared with each other. Rusults Experimental autoimmune uveitis could be induced in Lewis rats,F344 rats and Wistar rats with US-BMAA.Clinical and histopathalogical examination showed that bilateral ocular inflammation developed after immunization 9-13 days.Although inflammation was mainly located in anterior uvea,a mild focal choroiditis was noted in those with severe anterior inflammation.No inflammation was observed in the retina and pineal gland.Experimental autoimmune uveieis induced with USF-BMAA was similar to experimental autoimmune anterior uveitis incited with BMAA presented by other authors.Inflammation induced with USF-BMAA in F344 rats and in Lewis rats was quite similar in the severity and course of the model.But the inflammation was less in Wistar rats compared with that in Lewis rats and F344 rats. Conclusion Experimental autoimmune anterior uveitis was successfully induced with USF-BMAA in Lewis rats,F344 rats and Wistar rats.The difference with regard to the severity among these aminals were propably attributed to their genetic bankground. (Chin J Ocul Fundus Dis,1998,14:149-152)
Objective To quantify the mRNA expression of NMDAR1 gene in the retina of eyes with acute elevation of IOP in rabbit． Methods Tweenty-six eyes of 16 rabbits were divided into three groups: Group 1: The IOP of one eye in 10 rabbits was elevated to 60 mm Hg by ante ri or chamber infusion． Group 2: The another eye of the same rabbit in group 1 was maintained the IOP to 20 mm Hg by anterior chamber infusion． Group 3: Unilat eral eyes of six rabbits were enucleated to evaluate the mRNA levels as normal control group． PCR product was identified by Southern blotting and the mRNA expression level was quantified by RT-PCR． Results The results revealed no significant difference between group 1 and group 2． Conclusion This implies that acute elevated IOP may not affect the mRNA expression level of NMDAR1 gene． (Chin J Ocul Fundus Dis, 2001,17:50-51)
Objective To study the effects of neonatol rabbit Schwann cells(SC) on repair of optic contusion in adult rabbits. Methods 24 h after the adult rabbit optic nerves was contused,0.1 ml of SC suspension (group A) and saline water (group B) were injected into the vitreous of injured eyes respectively.All the animals were studied by retinal ganglion cell (RGC) and axon counting,flash visual evoked potential (FVEP) tests at various intervals after injury. Results At the 4th week after injury,the number of RGC was (19.89plusmn;3.79)/mm in group A and (12.67plusmn;4.12)/mm in group B,and the density of axons was (94.569plusmn;793)/mm2 in group A and (36.085plusmn;285)/mm2 in group B.There was dramatical difference between group A and B (Plt;0.01).The amplitude of FVEP wave of group A increased from 48% to 88% on the 3rd day after injury,and still dept 78% at the 8th week and group A was significantly higher than group B at various intervals (Plt;0.01). Conclusion SC are effective in promoting the repair of optic nerve contusion by increasing the survival rate of RGC,rescuing axons from degeneration,and dramatically promoting the function of the optic nerve. (Chin J Ocul Fundus Dis,2000,16:91-93)
ObjectiveTo observe the expression of CD147, matrix metalloproteinases-2 (MMP-2) and vascular endothelial growth factor (VEGF) in a rat model of oxygen induced retinopathy (OIR). MethodsEighty-four neonatal Wistar rats were divided into two groups randomly, the hyperoxia group (n=42) and the control group (n=42). Oxygen induced retinopathy was established in the hyperoxia group, the control group was raised in room air. Wholemonts were prepared from postnatal day (p) 7 and 14 rat retina to observe retinal vascular morphology. The number of endothelial cells to break through the internal limiting membrane was counted from p14 retinal paraffin sections. Expression of CD147, MMP-2 and VEGF protein levels was analyzed by immunohistochemistry on p12, p14, and p16 retinal sections. At the meantime, correlation between CD147 and MMP-2, VEGF was analyzed by two-way analysis of variance (ANOVA) test. ResultsAt p7, the retinal vasculature of the control group was radial distributed with large caliber. In OIR group, there were vasoconstriction, large area of avascular zone and a few small areas of vascular network. At p14, the normal untreated rat had interwoven retinal vasculature, but in OIR group, the retinal vasculature was expanded and tortuous, and forming lots of neovascular cluster in the boundary of the perfusion and non-perfusion regions resulting exudation and hemorrhage. At p14, the endothelial cell nuclei breakthrough the internal limiting membrane was (1.30±1.26) and (19.70±3.56) respectively in control and OIR group, the difference was statistically significant (t=21.813, P<0.01). Immunohistochemical staining showed that CD147, MMP-2, VEGF expression was low in control group but high in OIR group. From p12 to p16, CD147, MMP-2 and VEGF protein expression increased in OIR retinas compared with control samples(p12:t=5.612, 4.122, 4.955; P<0.01. p14:t=11.390, 8.047, 12.176; P<0.01. p16:t=6.355, 4.422, 5.110; P<0.01). ConclusionCD147, MMP-2 and VEGF were highly expressed in the rat model of oxygen induced retinopathy.
Objective To observe the histological changes and apoptosis of retinal cells in pigmented rabbits treated by transpupillary thermotherapy (TTT) with different laser power. Methods Fourteen pigmented rabbits (28 eyes) were divided averagely into seven groups（control group, 50, 70, 90, 110, 130, and 150 mW group）according to different laser power of TTT. Light microscopy was performed to observe the histological changes, and TDT-mediated biotin-dUTP nick-end labeling (TUNEL) technique and flow cytometry (FCM) examination were used to detect the apoptotic cells 24 and 48 hours after photocoagulation, respectively. Results The color of retinal burn speckles changed from offwhite to white and super white with the diameter enlarged gradually as the laser power of TTT increased. The results of light microscopy revealed that compared with the control group, the retinal tissue did not change much in 50-70 mW group; in 90-130 mW group, the retinal structure was integrated, but the cone and rod cells became swollen and condensed nuclei and cytoplasmic vacuolization were seen in the inner nuclear layer. The difference of retinal structure in 50-130 mW group 24 and 48 hours after photocoagulation and control group was not significant. In 150 mW group, tumefaction and degeneration were observed in each layer of retina and the inner and outer segments of photoreceptor cells lost 24 hours after photocoagulation, and obvious necrosis and cell loss of retinal tissues were detected hours after photocoagulation. The results of TUNEL examination indicated that positive cells were found in outer nuclear layer in each photocoagulation group which increased as the laser power of TTT was enhanced; the apoptosis gradually involved the inner nuclear layer and ganglion cell layer. The results of flow cytometry (FCM) examination showed the peak of apoptotic cells in each photocoagulation group 24 hours after photocoagulation. Conclusion Under certain subthreshold photocoagulation (50-70 mW), retinal tissue of rabbits does not change much but apoptosis of photoreceptor cells increase significantly. As the laser power of TTT increases, the retinal tissues become swollen, degenerated and even necrotic; cellular apoptosis gradually involves the inner nuclear layer and ganglion cell layer. (Chin J Ocul Fundus Dis, 2006, 22:249-252)
Objective To investigate the effect of suppression of ischemia-induced retinal neovascularization by VEGF antisense oligodeoxyribonucleotides. Methods Mouse models of hyperoxia-induced ischemic retinopathy were established. Retrobulbar injections were performed with VEGF antisense oligodeoxyribonucleotides or NS in 4 groups:normal control and various doses respectively. The nuclei of new vessel buds extending from the retina into the vitreous in differ ent groups were counted and compared under the light microscope. Results There were plenty of new vessel buds in the eyes of mice in hyperoxic condition., while the number of the nuclei of new vessel buds is less in the murine eyes with retrobulbar injection of VEGF antisense oligodeoxyribonucleotides,especially the nuclei were redused with 59.3% in eyes with large dose. Conclusion The proliferation of retinal new vessel may be suppressed by using the retrobulbar injection of VEGF antisense oligodeoxyribonucleotides. (Chin J Ocul Fundus Dis, 2001,17:141-143)
Objective To observe the affection of optic nerve under acute ocular hypertension and the effect of protection of bFGF on optic nerve. Methods BSS was perfused into anterior chamber of rabbits to increase the intraocular pressure to cause retinal ischemia. A computer image analysis system was used to count the optic nerve axons.Eyes were intravitreally injected with bFGF and then the number of optic nerve axons of the normal rabbits,and hypertension with and without bFGE treatment groups were counted respectively. Results The number of optic nerve axons in ocular hypertension eyes was less than the normal eyes(P=0.00003).The bFGF treated eyes had more optic nerve axons than the controls(P=0.0078). Conclusions The acute ocular hypertension may cause the loss of the nerve axons,and bFGF may be effective in protecting optic nerve in acute ocular hypertension. (Chin J Ocul Fundus Dis,2000,16:94-96)
Objective To investigate the damage to the retinal cells and apoptosis of retinal cells of rats after ischemia-reperfusion insult. Methods The retinal ischemia-reperfusion model was developed by increasing intraocular pressure to 109725 mm Hg in rat eyes. Morphological changes of the rat eyes were observed by means of routine histopathology with HE staining. Apoptosis of the retina was assayed by both DNA fragmentation gel-electrophoresis and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL). Results Compared with the normal control, no histopathological changes were revealed in the rat retinas 30 min after the ischemia and then reperfued for 24 h or 48 h. Retinal ganglion cell layer (RGL) and inner plaxiform layer (IPL) of the retina were observed, however, to become significantly thinner 60 min after the ischemia and then reperfued for 24 h or 48 h. Together with the pathological changes DNA ladder pattern was detected in the same group of the rats. Further, immunochemical stain of the eye demonstrated that TUNEL positive cells were localized in RGL and IPL of the retina. Conclusion Ischemia-reperfusion insult of the eye may remarkably damage the retina of the rat eye. The damage to the retinal cells is mainly localized within RGL and IPL and apoptosis is the important mechanism of the retinal disorder. (Chin J Ocul Fundus Dis, 2002, 18: 296-298)
Objective To detect expression of NF-κB in the inner retina and in vestigate the inhibitoryeffect of pyrrolidine dithiocarbamate on retinal neovascularization in rats. Methods The rat models with retinopathy were set up un der the hypoxia condition, and fluorescein fundus angiography (FFA) was used to observe the retinal neovascularization. The expressions of NF-κB in the inner retina in rats with and without neovascularization were detected by immunohisto chemical method. PDTC was intraperitoneally injected in rats with neovascularization to observe the expression of NF-κB in the inner retina and the effect on retinal neovascularization. Results Hypoxia induced NF-κB activation in the retinal glial cells and endothelial cells. But immuno-staining intensity for NF-κB and adhesion molecules were reduced by PDTC intraperitoneal injection. Retin al angiogenesis in rats were suppressed effectively (P＜0.05). Conclusions NF-κB activation correlates with retinal neovascularization closely. PDTC may inhibit the NF-κB activation and prove beneficial in the treatment of ischemic neovascularization. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To investigate the pathological spectrum of hypertensive retinopathy. Methods Systemic hypertension was produced experimentally in SD rats by partially constricting the right renal artery and removing the left kidney.The eyes obtained from hypertensive animals at 2 weeks,1,2,4months were examined by means of light microscopy,immunohistochemical staining,electron microscopy and histochemical electron microscopy and compared with the control group. Results 1.From 2 months after surgery,thickening of retinal capillary basement membrane(RBM)became apparent.2.From then on,RBM showed an increased staining reaction for type Ⅳcollagen and laminin,while staining reaction of RBM for fibronectin in hypertensive rats was negative at any stages.The number of anionic sites within the RBM was gradually reduced following the development of hypertension and it was definitely decreased at 4 months. 3.A few deteriorated endothelial cells were lifted focally from the RBM with subendothelial swelling in retinal vessels at 2 weeks,and the pericytes exhibited edema and deterioration at 4 months. Conclusions Detachment of the endothelial cells from the RBM,thickening of the RBM companied with the reduction of anionic sites and deterioration of pericytes may be responsible for hypertensive retinopathy. (Chin J Ocul Fundus Dis, 1999, 15: 163-166)