OBJECTIVE: To investigate the expression and signification of pigment epithelium-derived factor in choroidal neovascularization (CNV) induced by krypton laser on Brown Norway rat. METHODS: Five groups of 30 rats were photocoagulated by krypton laser in single eye to induce CNV. 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks after photocoagulation, The retina was processed for histopathology, in situ hybridization of PEDF mRNA, immunohistochemistry of PEDF and FVIIIR:Ag. RESULTS: CNV was formed 1 week after photocoagulation, and reached its peak at 3 weeks. PEDF mRNA, PEDF expressed in the ganglion cells, inner nuclear layer, retinal pigment epithelial cells in normal BN retina. After photocoagulation, the expression of PEDF mRNA and PEDF was observed in the ganglion cells, inner nuclear layer, retinal pigment epithelial cells, and the lesions of outer nuclear layer and choroid; the expression of PEDF in the lesions was weaker than that at the edge of the lesions. From 3 days to 4 weeks, the expression density of FVIIIR:Ag gradually increased, however, the expression density of PEDF mRNA and PEDF in the lesions decreased (P < 0.05). The expression of FVIIIR:Ag was inversely correlated with that of PEDF during the development of CNV (r = -0.84, P < 0.05). CONCLUSIONS: CNV is inversely correlated with PEDF. The down-regulation of PEDF may be one of the main reasons for the formation and development of CNV.
OBJECTIVE: To investigate the expression and signification of pigment epithelium-derived factor in choroidal neovascularization (CNV) induced by krypton laser on Brown Norway rat. METHODS: Five groups of 30 rats were photocoagulated by krypton laser in single eye to induce CNV. 3 days, 1 week, 2 weeks, 3 weeks and 4 weeks after photocoagulation, The retina was processed for histopathology, in situ hybridization of PEDF mRNA, immunohistochemistry of PEDF and FVIIIR:Ag. RESULTS: CNV was formed 1 week after photocoagulation, and reached its peak at 3 weeks. PEDF mRNA, PEDF expressed in the ganglion cells, inner nuclear layer, retinal pigment epithelial cells in normal BN retina. After photocoagulation, the expression of PEDF mRNA and PEDF was observed in the ganglion cells, inner nuclear layer, retinal pigment epithelial cells, and the lesions of outer nuclear layer and choroid; the expression of PEDF in the lesions was weaker than that at the edge of the lesions. From 3 days to 4 weeks, the expression density of FVIIIR:Ag gradually increased, however, the expression density of PEDF mRNA and PEDF in the lesions decreased (P < 0.05). The expression of FVIIIR:Ag was inversely correlated with that of PEDF during the development of CNV (r = -0.84, P < 0.05). CONCLUSIONS: CNV is inversely correlated with PEDF. The down-regulation of PEDF may be one of the main reasons for the formation and development of CNV.