The Study Of Celecoxib Inhibits Experimental Choroidal Neovascularization

Objective:Choroidal neovascularization is the pathologic neovascularization of choroid which invade subretinal space or under RPE. It is one of the leading blind disease in the world,and become difficulty of ophthalmology.Many experiment confirmed that there was a close relationship between inflammation and CNV. Many kinds of vascular growth factors released by active inflammatory cells and proteinases come into being a complicated net system,which promote CNV greatly.Celecoxib, a highly selective cyclooxygenase-2 inhibitor, is a kind of ordinary non-steroid anti-inflammatory drugs,was found effective to inhibit tumor growth and metastasis by decreasing neovascularization of the tumor. This article was designed to probe the mechanism and therapy of CNV through observe the express of COX-2,VEGF and MMP-2 in CNV membrame and the effect of COX-2 inhibitor celecoxib on the experimental CNV model induced by laser photocoagulation .Methods:1 The study of experimental CNV model1.1 Experimental eyes in 10 healthy(Brown Norway)BN rats (one experimental eye and one control eye per rat)were received a series of 9 Krypon laster (647nm wave length,50μm spot size,360mW power,0.05 second duration) lesions around the optic nerve head per experimental eye.1.2 Fundus fluorescein angiography (FFA) was performed on days 3,7, 14, 21,30.1.3 6h later,the rats were sacrificed,then the eyes were enucleated and processed.Chose"the thickest CNV membranes"for histopathologic examination.1.4 Chose the rats on days 21 after photocoagulation for the examination of electron microscope.1.5 Statistical analysis was performed by t-test and one-way ANOVA by SAS V8.2 The expression of COX-2,VEGF and MMP-2 in CNV membranes of the experience CNV model2.1 Retinal sections on different date of each group were chosen to detect COX-2,VEGF and MMP-2 by immunohistochemistry examination.2.2 HPIAS-1000 image analysis system was used to compare test result.2.3 Statistical analysis was performed by X2 test, t-test,test for distribution of normal and linear correlation analysis by SAS V8.3 The study of celecoxib inhibits CNV in an experimental model of CNV in the BN rats3.1 25 healthy rats were randomly divided into 3 groups including the control group, laser group and Celecoxib group. Celecoxib was administrated in celecoxib group by oral gavage (50 mg/kg,twice one day).After 1 week, experimental CNV was induced by Krypon laster (647nm wave length,50μm spot size,360mW power,0.05 second duration) on laser group and celecoxib group.3.2 Fundus fluorescein angiography was performed on days 3,7, 14, 21,30 afer laser photocoagulation.3.3 On days 21 after photocoagulation the rats were sacrificed,the eyes were enucleated and processed the normal and"the thickest CNV membranes".3.4 Calculate the relative thickness of CNV membranes by histopathologic examination.3.5 The expression of COX-2,VEGF and MMP-2 was surveyed by immunohistochemistry examination.2.6 Statistical analysis was performed by X2 test and t-test by SAS V8.Results:1 The study of experimental CNV model1.1 CNV was firstly appeared on days 7 after photocoagulation, reaching the peak on days 21. The incidence of CNV was 77.78%.1.2 FFA showed hyperfluorescence in early stage and fluorescence leakage significant in late stage.1.3 It was identified that CNV invade subretinal space or under RPE by light and electron microscope. Aslo macrophages,RPE cells,fibroblasts were seen. 1.4 The relative thickness of the CNV membranes also changed with the time. It was increasing on days 7-21 after photocoagulation,reached the peak on days 21,and it was not change markedly later.2 The expression of COX-2,VEGF and MMP-2 in CNV membranes of the experience CNV model2.1 It found the immunohistochemistry examination of COX-2,VEGF and MMP-2 was positive in CNV membranes. It found that they had the same change trend with the time.2.2 The expression was increasing clearly on days 7-14 after photocoagulation,and reached the peak on days 21,then declined a little.2.3 there were correlation between COX-2,VEGF and MMP-2.3 The study of celecoxib inhibits CNV in an experimental model of CNV in the BN rats3.1 CNV reaching the peak on day 21 after photocoagulation and it shows that the incidence of CNV is clearly difference between laster group and celecoxib group on FFA(x2=7.1068 P=0.0077).3.2 Also the relative thickness of the CNV membranes is significant difference between the two groups on days 21 after photocoagulation(P<0.01),it decreased 41.38% on celecoxib group.3.3 Immunohistochemistry examination of COX-2,VEGF and MMP-2 in CNV membranes indicated that they were significantly decreased of celecoxib group on days 21 after photocoagulation(P<0.01).Conclusion:1 The experimental model of CNV can be induced by Krypon laster in BN rats with a stable,trusty,cheap and use a short time to receive a high successful rate.2 Many inflammatory cells such as macrophages and obvious inflammatory reaction were seen in CNV by laser photocoagulation.3 Inflammtion induced active COX-2,which increaced the expression of many kinds of vascular growth factors and proteinases. The expression of COX-2,VEGF and MMP-2 in CNV membranes of the experience CNV model was increased ,and there were correlation between COX-2,VEGF and MMP-2.4 Celecoxib can reduce the incidence of CNV by laser photocoagulation through inhibit the expression of COX-2, which can increase VEGF and MMP-2 express.