Objective To observe the pathological and functional changes of retinal photochemical damages exposed to green flurescent light. Methods The Sprague Dawley rats were continually exposed to green fluorescent light with an illuminancem level of (1 900plusmn;106.9) Lx for 24 hours.The changes of retinal morphology and morphometrics and flash electroretinogram were studied before light exposure and at the 6th hour,6th day and 14th day after light exposure. Results At the 6th hours after light exposure,the outer nuclear layer(ONL)of retina becoma thinner compared with that bfore light exposure.The thickness of ONL decreased by 23.91% and the inner and outer segments appeared disorderly arranged.At the 6th day after light exposure the thickness of ONL is thinner than that at the6th hour,i.e.decreased by 46.6%. At the 14th day after light exposure the thickness of ONL decreased by 42.40%.Flash electroretinogram showed that the amplitudes of a and b wave decreased continuously at the 6th hour and 6th day and unrecovered at the 14th day after light exposure. Conclusion This model might be an ideal one for research on retinal photochemical damage. (Chin J Ocul Fundus Dis,1998,14:101-103)
Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12，24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)
Objective To investigate the expression of T cell receptor (TCR) Vβ8.3 gene on CD4+ T lymphocytes in the rats with experimental autoimmune uveoretinitis (EAU). Methods Eighteen Lewis rats were divided into EAU, complete Freund′s adjuvant, and the control group. Inter photoreceptor retinoid-binding protein (IRBP) R16 peptide was synthesized using Fmoc procedure for induction of EAU. Magnetic absorption cell sorting (MACS) me thod was used to isolate the CD4+T lymphocytes from the spleen of the rats. Flow cytometry was used to monitor the efficiency of isolation. The expression of TCR Vβ8.3 gene segment on CD4+T lymphocytes was determined by fluorescent quantitative polymerase chain reaction. Results EAU was successfully induced in the Lewis rats immunized with IRBP R16 peptide. The proportion of CD4+T lymphocytes isolated by means of MACS was statistically higher than that before isolation (P＜0.001). The expression of TCR Vβ8.3 gene segment on CD4+ T lymphocytes in EAU rats was significantly higher than that in the control (P＜0.05). Conclusions There is a predominant usage of antigen-specific TCR Vβ 8.3 gene in EAU rats induced by IR BP R16 peptide, which may serve as a target for immunotherapy of EAU. (Chin J Ocul Fundus Dis，2004，20：165-167)
Objective To evaluate the effect of vascular endothelial cell growth factor (VEGF) antisense oligodeoxynucleotides (ASODNs) on the expression of VEGF in rats with oxygen-induced retinopathy. Methods Thirty newborn Sprague-Dawley (SD) rats were randomly divided into 3 groups:normal control group, disposal group and non-disposed group, The animal models with oxygen-induced proliferative retinopathy were established by raising the rats in hyperoxic environment. Retrobulbar injection was performed with VEGF ASODNs or normal saline on the rats in 3 groups respectively. The intraocular tissues (all the tissues except the cornea, sclera, and lens) and serum were collected, and the expressions of VEGF were determined by using competitive enzyme immunoassay.Results The expressions of VEGF in intraocular tissues of rats in disposal group were significantly lower than those in non-disposed group (P＜0.05), and there was no statistical difference between the disposal and normal control group (P＞0.05). There was no significant difference of the expressions of VEGF in serum of rats between the disposal and non-disposed group (P＞0.05), which were both lower than those in the normal control group (P＜0.05). Conclusion VEGF ASODNs could significantly inhibit the expression of VEGF in intraocular tissues. (Chin J Ocul Fundus Dis，2003，19：172-174)
Objective To explore the effect of ischemia-reperfusion injury on the retinal functions of rats. Methods Seventy Wistar rats were selected, 20 of which were selected randomly and divided into two groups (control group and single-irrigated group). The rats were anesthetized and their anterior chambers of the right eyes were cannulated with a 7-gauge needle connected to a reservoir containing ringers balanced salt solution, which was maintained at the same level o f the eye for 1 hour. After that, ERG was recorded in both eyes of all rats. All the left rats were divided randomly into 10 groups and they were treated as the single-irrigated group. Retinal ischemia was induced by raising the reservoir to a height of 150 mm Hg. One hour later except the single ischemia group, all o f t he groups resumed perfusion after 3,6,12,and 24 hours and 3,5,7,14,and 21 days s eparately. ERG was recorded in both eyes of all rats.Results There was no difference in the results of ERG between left and right eyes in either the control group or the single-irrigated group. All the waves of ERG vanished in the single-ischemia group after 1 hour. In the ischemia-reperfusion groups, the waves of ERG partly recovered and the amplitude reduced persistently and progressively.Conclusion Ischemia-reperfusion injury may affect the function of the retina persistently and progressively. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To observe the expression of erythropoietin (EPO) and its receptor (EPOR) mRNA and protein levels in retinae of mice with oxygen-induced retinopathy, and to evaluate the effect of EPO and EPOR in retinal vascular develo pment and in the occurrence and development of oxygen-induced retinopathy. Methods One hundred and thirty-two 7-day-old C57BL/6J mice were divided into two g rou ps: normal control group (control group) and oxygen-induced retinopathy group (experimental group). The proliferative neovascular response was estimated by obse rving the vascular pattern in adenosine diphosphatease (ADPase) stained retina flat-mounts by executing 6 mice in each group at the 12th, 15th, and 17th day, respectively. The expression of EPO, EPOR mRNA was determined by reverse transcription-polym erase chain reaction (RT-PCR), and the protein levels of EPO and E PO R were determined by immunohistochemistry. RT-PCR and immunohistochemistry were done every other day from the 7th to the 21st day. Results In the control group, retinal vascularization was found. In the experimental group, the large vesse ls were constricted straight, the branches decreased, and alarge nonperfusion area was observed at the 12th day; the large vessels were dilated and tortuous and neovascularization occurred at the 15th day; a mass of neovascularization was found and the vascular net structure of the deep and shallow layer was destroye d at the 17th day. The expression of EPO mRNA decreased from the 7th day and kee p decreasing in the whole oxygen-breathing duration in the experimental group. A fter the mice were returned to room air, the expression increased obviously from the 15th day and kept the high level until the 21st day. The expression of EPO mRNA increased at the 7th day and reached the peak at the 11th day, and kept the high level until the 21st day. The changes of protein levels of these three fac tors were later than that of their mRNA, but had the same trend. The difference of the expression between the two groups at the different time point was signifi cant except for the 7thday point (Plt;0.05). Conclusion It 's suggested that EPO and EPOR played important roles on the development of normal retina vascularizati on and the pathogenesis of ROP, which may provide new conception and method for the prevention and treatment of the oxygen-induced retinopathy.
ObjectiveTo investigate the expression and relation of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in rats with diabetic retinopathy.MethodFifty-five Wistar rats were randomly divided into the control group (10 rats), and 1, 3, and 5-month-diabetes group (15 rats in each diabetes group), and the diabetic models were set up. The expressions of VEGF and bFGF were detected by situ hybridation and immunohistochemistry on retinal paraffin sections.ResultsThe results of situ hybridation showed that expression of bFGF was found in 3-month-deatbtes group with the percentage of 77.8%, and 88.9% in 5-month-deatbtes group; the positive expression of VEGF was not found in 3-month-deatbtes group but in 5-month-deatbtes group with the percentage of 66.7%. Immunohistochemistry indicated that the positive expression of bFGF started in 3-month-deatbtes group with the percentage of 55.6%, and 88.9% in 5-month-deatbtes group; the percentage of the expression of VEGF was 33.3% in 3-month-deatbtes group and 88.9% in 5-month-deatbtes group.ConclusionThe expression of VEGF occurs after the expression of bFGF in rats with DR.(Chin J Ocul Fundus Dis, 2005,21:37-40)
Objective To investigate the effect of hepatocyte growth factor (HGF) on the barrier function of retinal peigment epithelium (RPE) and to detect the pathological mechanism of retinal detachment (RD) induced by over expression of HGF in RPE. Methods Sub-retina injection of E1/E3deleted adenoviral vectors encoding HGF (Ad CMV.HGF) and green fluorescent protein (Ad CMV.GFP) in adult pigmented rabbits [5times;104 plaque-forming units (pfu)/eye] to set up the model of retinal detachment. The ocular fundus and pathological changes were observed 3, 7, 14, and 28 days after injection. The expression level of HGF in retina and vitreous body was detected by immunohistochemistry and enzyme linked immunosorbent assay (ELISA). Results In the control eyes injected with AdCMV.GFP, expression of GFP only detected in RPE monolayer. The eyes injected with AdCMV.HGF had b HGF immune positive action in RPE cells at the injection site. The expression level of HGF in vitreous body reached the peak 7 days after injection and decreased to the basic level 28 days after injection. Chronic RD and chronic choroidal inflammation were found in the eyes injected with AdCMV.HGF within the time frame of HGF expression. Proliferative RPE cells were found in subretinal space in the region of RD, and multilayered cellular membranes developed in some eyes. Conclusion Over expression of HGF in RPE may induce chronic serous RD with subretinal proliferation of RPE, which suggests that HGF should be further studied as a target for therapeutic intervention in RD. (Chin J Ocul Fundus Dis, 2007, 23: 193-197)
Purpose To determine the effect of exogenous interleukin-1alpha; (IL-1alpha;) on the retina and its vasculature and VEGF expression in SD rats． Methods IL-1alpha;2．0 ng (20 mu;l) were injected into the vitreous of 8 left eyes of 8 SD rats while steriled PBS were injected into 8 right contralateral eyes of the same rats as control． All eyes were assessed by direct ophthalmoscopy every day and enucleated on the 7 thpostoperative day． Histological examination (hemato xylineosin staining) and immunohistochemical staining with antibody against VEGF antigen were performed， and sections were observed and photographed under light microscopy． Results ①All 8 IL-1alpha; inject ed eyes developed epiretinal membranes and extraretinal neovascularization on the 3 rd postoperative days while none of the 8 control eyes exhibited any a bnormal retinal vascular changes and they were confirmed by HE staining;②Immuno staining identified VEGF express mainly in the inner layer of vessel walls， the epiretinal membranes， the neuroganglional layer and the photoreceptor layer of retina， while the control eyes showed only weak positive staining in the photo receptor layer． Conclusions IL-1alpha; is capable of inducing vitreo retinal neovascularization，and increasing the expression of VEGF in the retina and epiretinal membranes． (Chin J Ocul Fundus Dis, 2001,17:135-137)
Objective To investigate if insulin can affect the expression of vascular endothelial growth factor (VEGF) in the retina of streptozotocin-induced diabetic rats. Methods A total of 60 male SpragueDawley rats were randomly divided into sodium citrate buffer control group (CIT-CON, n=30) and STZ-induced diabetic group (STZ-DM, n=30). At the 16th week, 24 rats from CIT-CON group at random were randomly divided to group A (sodium citrate buffer control group, n=12) and group B (sodium citrate buffer plus insulin group, n=12). The remaining 6 rats from as CIT-CON group served as negative control. At the same time, 24 rats from STZDM group at random were randomly divided to group C (STZinduced diabetic group, n=12) and group D (STZ-induced diabetic plus insulin group, n=12). The remaining 6 rats from STZ-DM group also served as negative control. 4 IU of insulin was injected subcutaneously to rats of group B and D. Immunohistochemistry, Western blot and Real-time polymerase chain reaction (RT-PCR) were used to measure the expression level of VEGF protein and mRNA respectively. RESULTS Insulin significantly increased the VEGF mRNA (7.71plusmn;0.25 vs 5.36plusmn;0.37, t test Plt;0.05) and protein expression (0.4925plusmn;0.0122 vs 0.4272plusmn;0.0110, t test Plt;0.05) in the retina of CITCON rats. However, in retina of STZDM rats, insulin had no effect on VEGF mRNA (8.92plusmn;0.27 vs 9.05plusmn;0.28, t test, Pgt;0.05) and protein expression (0.5152plusmn;0.0109 vs 0.5099plusmn;0.0100, t test Pgt;0.05). Conclusions Insulin had no effect on VEGF expression in the retina of STZ-DM rats.