Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)
Objective To investigate the expression and significance of inducible co-stimulator (ICOS) in experimental autoimmune uveoretinitis (EAU). Methods EAU was induced in 24 Lewis rats (immune group) by immunization with retinal S-antigen (50 mu;g) and complete Freundprime;s adjuvant, and another 4 rats were in the control group. Anterior segment of the ratsprime; eyes were observed by split microscope every day. Immunohistochemical staining was performed using polyclonal antibodies to ICOS on the sections of the spleen which were obtained from the rats in immune group at the 7th, 12th, 15th and 21st days after immunisation respectively. Western blotting was performed to investigate the dynamic expression of ICOS protein in the spleen. The same procedures were made at the corresponding time points in the rats in control group. Results A few ICOS positive cells were observed in the normal spleen. The number of ICOS positive cells in immune group increased obviously at the 7th and 12th days after immunization, reached the peak at the 15th day, and decreased at the 21st day which was still higher than that in the control group. The result of Western blotting showed that the dynamic changes of ICOS protein was identical with the changes of positive-cell number detected by immunohistochemistry. Conclusions The enhanced expression of ICOS happens before EAU occurs, which increases when the inflammation occurs and deteriorates, and decreases at the alleviative stage of EAU. It suggests that ICOS participates in the formation, development and disappearance of EAU and plays an important role in the incidence of EAU. (Chin J Ocul Fundus Dis, 2005,21:114-117)
ObjectiveTo observe the expression of connective tissue growth factor (CTGF) in injured model of retinal pigment epithelial (RPE) cells and the promoting effect of CTGF on migration of RPE cells.MethodsCultured monolayer-confluent human RPE cells were scraped with a trephine and a cotton stick, and set up the injured model of RPE cells with round scraped area. Immunohistochemistry and in situ hybridization(ISH) were used to detect the expression of CTGF protein and mRNA in injured RPE cells at distinct time points after injury. The number of RPE cells migrated to injured area was measured and the effect of CTGF on migration of RPE cells and the effect of dexamethasone (DEX) on the promoting process of CTGF were observed.ResultsThe results of immunohstochemistry and ISH indicated the weak positive expression of CTGF in RPE cells at the edge of scrape 6 hours after injury, and the positive expression increased gradually as time goes by after the injury. Strong positive expression of CTGF in RPE cells at the edge of scrape was found 24 and 48 hours after injury. Rebuilt human CTGF stimulated migration of RPE cells in a dose-depended manner, and DEX significantly inhabited the migration.ConclusionCTGF involves in the procedure of repair of injury of RPE cells, which may play an important role in the pathogenesis of intraocular proliferative diseases such as proliferative vitreoretinaopathy.(Chin J Ocul Fundus Dis, 2005,21:306-309)
Objective To establish an allogenic intraocular melanoma model and observe its pathological features.Methods Thirty-six kunming mice were devided randomly into 3 groups with 12 ones in each, and allogeneic melanoma cells B16F10(C57BL16) were inoculated into the anterior chamber (AC), vitreous cavity (VC) of right eyes and under the skin (subcutaneous, SC) of the back of right feet of each grup respectively. The incidence of tumor occurance, time of breaking through the eyeball and other general pathologic features of the tumor were observed by slip-lamp biomicroscopy and operating microscopy for continuous 32 days, and the results were statistically analyzed. Pathological examination was given for tumors at last.Results The incidence of tumor occurance in both AC (12/1 2 eyes) and VC group (11/11 eyes) was higher than that in SC group (2/12 feet)（χ2=17.143, P＝0 .000；χ2=16.218, P=0.000）. The time of eyeball diabrosis was 11-13 days in AC group and 13-32 days in VC group, and there was significant difference between these two groups (Log Rank=18.22, P=0.000). The intraocular melanomas could grow progressively, but reduced and fell off when they broke through eyeball and grew in or bit for a period. The average diameter of the tumor after 32 days after inoculation was (2.27±1.97) mm in AC group，(3.82±1.85) mm in VC group and (0.94±2.27) mm in SC group. There was significant difference between VC and SC group (t=3.322，P=0.003). In pathohistological examination, tumor tissue necrosis could be observed at the center of the subcutaneous melanomas but not in intraocular melanomas.Conclusions Allogeneic intraocular melanoma model is successfully established which is convenient, repeatable, and helpful to studying the mechanism of genesis and development of this tumor. (Chin J Ocul Fundus Dis，2003，19：333-404)
ObjectiveTo analyze the regulative rule of mRNA of vascular endothelial growth factor (VEGF) in mice with oxygen-induced retinopathy, and to elucidate the possible mechanism of occurrence of neovascularization in retinopathy of prematurity (ROP).MethodsSixty 7-day-old C57BL/6J mice were divided into oxygen-induced retinopathy group and control group. In oxygen-induced retinopathy group, 36 mice were exposed to 75% oxygen for 5 days and then to room air for 5 days; in control group, 24 mice were raised in room air. Vascular perfusion of fluorescein and retinal stretched preparation were used to observe the morphologic changes of retinal vessels. Reversal transcriptionpolymerase chain reaction (RT-PCR) was used to observe changes of VEGF mRNA in each group. ResultsIn oxygen-induced retinopathy group, the morphologic characteristics of retinal vessels were the unperfused area at the center of superficial and deepseated vessels, and the neovascularization appeared at mid-peripheral retina after 2 days in relative hypoxia condition. The results of RT-PCR showed space-time corresponding relation between expression of VEGF and neovascularization, which meant that the transcription of VEGF mRNA decreased in hyperxia conditionand increased in relative hypoxia condition. ConclusionHypoxia is the main reason of occurrence of retinal neovascularization; increased expression of VEGF caused by relative hypoxia after hyperxia might be effective in reducing the occurrence of neovascularization in ROP.(Chin J Ocul Fundus Dis, 2005,21:292-295)
Objective To investigate the expression of matrix metallo proteinase (MMP)-2 and MMP-9 in rats′optical nerves after extrusion wound. Methods We set up the model of rats with extrusion wound of the optical nerves, detected activity changes of MMP-2 and MMP-9 in the optical nerves by gelatin zymography, identified the attribute by Western blotting, and verified the expression of mRNA of MMP-2 and MMP-9 by reverse transcriptase-polymerase chain reaction (RT-PCR ). Results MMP-2 existed in normal optial nerves and optical nerves with extrusion wound, while MMP-9 was only detected in the latter. The expression of MMP-9 was the highest 1 day after the extrusion wound, while that of MMP-2 was the highest 7 days after the extrusion wound. Conclusions MMP-2 and MMP-9 may participate in the pathological recovery process of optical nerves after extrusion wound. The glial cells in the optical nerves may be one of the sources of MMP-2 and MMP-9. (Chin J Ocul Fundus Dis，2003，19：269-332)
Objective To investigate the degenerative changes in the inner rat retina after photic injury.Methods After 24 hour-dark adaptation, sixty Lewis rats were exposed in a ventilated green plexiglass chamber that transmitted continuous green light between 480-520 nm with an intensity of 900～1 000 lx. After 24 hour exposure, the rats stayed in darkness and were sacrificed after 1 day, 3,7 or 14 days. The neurons in the inner retina were marked by immunohisto chemical technique and observed by light and electronic microscope.Results The apoptotic photoreceptor cells were noted after photic injury. The degeneration and decreasing number of rod bipolar cells were found after 3 days; the edema of horizontal cells occurred after 1 day but ameliorated gradually; decreasing number of amacrine cells was found after 1 day; sustained edema of ganglion cells and prolifeeration of the Müller cells were found after photic injury. Pyknotic and edematous neruronal degenerations of inner retina were found in ultrastructural study.Conclusion The neurons in the inner retina as well as Müller cells are involved in the degeneration after photic injury. Different neurons manifest different patterns of degeneration.(Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To observe the inhibitory effect of Bevacizumab on retinal neovascularization in oxygen-induced retinopathy in the mouse. Methods 90 one-week-old C57B L/6J mice were divided into four groups at random. 15 mice in the 1st group as normal control group, 15 mice in the 2nd group as oxygen control group, 30 mice in the 3rd group as high-dose Bevacizumab treatment group, 30 mice in the 4th group as low-dose Bevacizumab treatment group. The 2nd, 3rd and 4th groups were exposed to 75% oxygen for 5 days and then to room air. At the 12th day, One eye of each mouse of two control groups were received an intravitreal injection with Be vacizumab at 2 mu;l、1 mu;l respectively, and the same volume of BSS was injected into the other eye of the mice. The adenosine diphosphatase (ADPase) histochemical technique was used for retinal flat mount to assess the oxygen-induced change s of retinal vessels. The number of the endothelium cell nuclei of proliferative neovascularization was quantified by retinal microtome chromoscopy. Real-time PCR analysis was performed to examine the expression of VEGF mRNA. Results Comparing with oxygen control group, regular distributions, reduced density of retina l vascular and reduced endothelium cell nuclei which extending retinal membrane were observed in the treatment groups(P＜0.001). But the differences between two treatment groups are not statistically significant (P＞0.05). The expression of VEGF mRNA was not significantly different in oxygen control group whatever it whether accepted Bevacizumab treatment or high or low dose (P＞0.05). Conclusion Intravitreal injection with Bevacizumab can effectively inhibits the retinal neova scularization in oxygen-induced retinopathy in the mouse. Intravitreal injection with Bevacizumab might become to the new method to treat retinopathy of premature. （Chin J Ocul Fundus Dis，2008，24：184-188）
ObjectiveTo explore the effect of estrogen on the permeability of retinal blood vessel by ovariectomy.MethodsTwenty-two healthy rats were divided into experimental and control group randomly. Estrogen level of rats decreased due to ovariectomy in the experimental group while stabilized by sham-ovariectomy in the control group. The results were confirmed by vaginal epithelium smearing. Retinal vein occlusion was established by photodynamic method, and leakage of Evan's blue in retina was determined by spectrophotometer.ResultsMature value of vaginal epithelium decreased significantly in ovariectomy rats（t=21.008，P=0.000） while not significantly in sham-ovariectomy ones （t=0.319，P=0.756）; the mean leakage of Evans blue was (25.503 0±4.378 47) ng/mg in experimental group, and (17.830 0±4.265 69) ng/mg in the control group, and the difference between the two groups is significant（t=3.969 36，P=0.001）.ConclusionOvariectomy is an useful method to study the effect of estrogen on ocular diseases, and when estrogen level decreases, the permeability of retinal blood vessel increases.(Chin J Ocul Fundus Dis, 2005,21:174-176)
ObjectiveTo evaluate the protective effect of estrogen on survival of retinal ganglion cells (RGCs) after transient retinal ischemia-reperfusion (RIR) in rats.MethodsRIR was induced in 60 ovariectomized adult rats (OVX) by increasing intraocular pressure via an intracameral catheter. All of the rats were divided into two groups randomly: in experimental group, the rats underwent a subcutaneous injection with 17β-estrodiol（100 μg/kg） 2 hours before retinal ischemia; and in the control group, saline water was injected correspondingly. The number of RGCs and the thickness of the inner retinal layers were mesured by HE staining method before and 12, 24, 48, and 72 hours after reperfusion. TdT-mediated biotin-dUTP nick end labelling (TUNEL) staining technique was used to examine the apoptosis of RGCs.ResultsTwenty-four and 48 hours after reperfusion, the number of apoptotic cells in experimental group was obvious lower than that in the control group(Plt;0.05), and the number of RGCs in experimental group was higher than that in the control group(Plt;0.05).ConclusionEstrogen can protect retinal neurons from transient RIR in ovariectomized rats.(Chin J Ocul Fundus Dis, 2005,21:177-179)