Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure （IOP）． Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber；then the pressure was released and the needle inserted into the anterior chamber was removed，this state was maintained for another 45 min．Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated．Aliquots（20 μl）of the retinal extracts（see below）were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei，using a 150 mm×4.6 mm,5 μm C18 column． Results A large increase in the release of glutamate，but not of the other three amino acids monitored，occurred during initial experimental ocular hypertension．It reached peak value of（111.73±17.46）10-5 mmol/g at 15 min of hypertension．15 min after release of intraocular pressure，again，immediately large and specific increase in the concentration of glutamate was reached to（102.96±51.91）10-5 mmol/g．In eyes subjected to paracentesis of anterior chamber，no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP，and it releases not only during the period of experimental ocular hypertension，but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
PURPOSE:To investigale the influence of orally administered aldose reduetace inhibitor(ARI) and myo-inositol (MI)for contents of gluecose,sorbitol and myo-inositol in experimental diabetic retinal tissue in rat. METHODS :The STZ-induced diabetic rats were administered ARI or MI by oral. The glucose sorbitol and myo-inositol in retinal tissues were analysed by high performance liquid chromatography after experimental period of 6 montbs. RESULTS:It was found that the contents of glucose and sorhitol were increased and myo inosltol was decreased in diabetic group. In diabetes with ARI group.the content of sorbitol was increased although the glucose was in high level. In diabetes wilb MI group,the sorbitol accumulaled and coment of myo-inositol was close to the normal control group. CONCLUSIONS:The ARI can effectively obstruct sorbitol accumulation in retina. MI increase myo-inositol level but fail to reduce sorbitol contenl of retina. （Chin J Ocul Fundus Dis,1997,13: 75-77 ）
Objective To observe the effects of high concentr at ion glucose on the calcium-activated potassium channel of rabbits′ retinal Müller cells. Methods The rabbits′retinal Müller cells were cultured in vitro under the condition of high concentration glucose, and identified by immunohistochemical staining and transmission electron microscopy. Patch-clamp technique was used to observe the changes of the calcium-activated potassium channel of retinal Müller cells caused by high concentration glucose at different time.Results High concentration glucose could inhibit the calcium-activated potassium channel of cultured retinal Müller cells in a time-dependent manner. Conclusion High concentration glucose may reduce the biological functions of Müller cells by inhibiting calcium-activated potassium channel. (Chin J Ocul Fundus Dis，2003，19：164-167)
OBJECTIVE:To observe the effect of dexamethasone to intracellular free Ca2+ of frozen RPE cells. METHODS:The cultured human RPE cells were frozen for 30s at --70deg;C. The RPE cells were loaded with Fura-2/AM and analyzed using a digital imaging microscopy system,the effect of dexamethasone to intracellular free Ca2+ was measured at a serial concentration of 40, 60,100,150,200mu;g/ml. RESULTS:The concentration of intracellular free Ca in frozen human RPE cells was increased to 18.6%~29.8% by dexamethasone at concenlration of 40mu;g/ml~60mu;g/ml,while was decreased to 28.4%~35.2% at 150mu;g/ml~200mu;g/ml. CONCLUSIONS:Effect of dexamethasone showed two aspects of effect to frozen cultured human RPE ceils,that it was inhibitor at high concentration and stimulator at low concentration （Chin J Ocul Fundus Dis,1997,13: 86-88）
Objective To observe the expression of N-cadherin in streptozotocin (STZ)-induced diabetic Sprague-Dawley (SD) ratsprime;retinae. Methods Celiac injection with 65 mg/kg STZ was performed on 20 rats to set up the diabetic model, and celiac injection with the same volume citrate buffer was performed on other 20 SD rats as the control. Vascular permeability was detected by Evans blue method. The expression of N-cadherin in both normal and STZ-induced diabetic ratsprime;retinae and trypsinase-digested retinal microvessels were detected by immunohistochemistry method and Western blotting analysis. Results Retinal vascular permeability increased 68%, 91% and 125% 4, 8, and 12 weeks, respectively, after diabetic models was induced (Plt;0.005). In the control group, the expression of N-cadherin was detected in the outer and inner plexiform layer, inner nuclear layer，ganglion cell layer,internal limiting membrane and between retinal endothelial cells and pericytes. However, the expression of N-cadherin significantly decreased in STZ-induced diabetic rats retinae at the 12th week. The results of Western blotting analysis showed that the expression of N-cadherin obviously decreased as the diabetic retinopathy developed. Conclusion The decrease of expression of Ncadherin in the retinae of STZ-induced diabetic rats suggests that N-cadherin may participate in the development of diabetic retinopathy at the early stage. (Chin J Ocul Fundus Dis,2007,23:269-272)
Objective To investigate the expression and characteristics distribution of ciliary neurotrophic factor (CNTF) and its receptor during the development of retina of healthy Sprague-Dawley（SD）and Royal College of Surgeons (RCS) rats with hereditary retinal degeneration. Methods The expression and distribution of ciliary neurotrophic factor and its receptor were detected by immunohistochemical staining in the retinal paraffin sections of SD and RCS rats from newborn to 12 moths old. Results In the normal retina of SD rats 0-7 days after birth, positive CNTF staining was found in all of the retinal layers and the staining of ganglion cells strengthened and other cells weakened as the age of rats increased; the staining of ganglion cells reached the peak at the 4th week and lasted till the agedness. The same results of the CNTF staining were also found in RCS rats retina. Weak positive staining of CNTFR in all of the retinal layers was seen in the 0-3-day-old SD rats; the ganglion cells were darkly stained and incontinuous positive staining at the site which would develop to be the external segment was found; as the age increased, the positive staining of external segment of photoreceptor enhanced and reached the peak at the 14-28th day after birth. At the 56th day, the staining of ganglion cells in retina of SD rats was strengthened while the staining of external segment weakened till the agedness. The expression of CNTFR in retina of 3-14-day-old RCS rats was the same as which of normal SD rats basically, but the staining of external segment weakened obviously from the 21st day on, and negative staining of external and positive ganglion cells were detected at the 28th day till the agedness. Conclusions Expression of CNTF in normal SD rats and RCS rats with hereditary retinal degeneration is almost the same. The presence of significant difference of expression of CNTFR between normal SD rats retina and RCS rats retina may provide the experimental gist for the CNTF treatment to retinal degeneration. (Chin J Ocul Fundus Dis, 2006, 22: 120-123)
Objective To determine the expression of the growth factors and the receptors related to angiogenesis in the intraocular tissues incarcerating in the sclerotomy sites. Methods Ten specimens from prolapsing intraocular tissues in sclerotomy sites during vitrectomy were obtained and serially sectioned in cryostate and were stained with a group of polyclonal antibodies against vascular endothelial growth factor(VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor-A(PDGF-A) and transforming growth factor-β1(TGF-β1) as well as their receptors by using a streptavidin peroxidase system. Results The tissues prolapsed from the sclerotomy sites were identified as retina(3 cases), vitreous tissues(3 cases), degenerated red blood cell components(2 cases), ciliary body(one case) and fibrous tissue(one case). All specimens expressed VEGF and bFGF as well as their receptors. PDGF-A, TGF-β1 and their receptors expressed in the most of specimens. The positive cells included retinal cells, ciliary non-pigmented epithelial cells and pigmented epithelial cells, fibrous cells and the cells in vitreous. Conclusions The intraocular tissues incarcerated in the sclerotomy entries express the growth factors and receptors related to angiogenesis. This might be one of the potential factors of developing anterior proliferative vitreoretinopathy. (Chin J Ocul Fundus Dis, 2002, 18: 34-37)