Experimental choroidal neovascularization is inhibited by subretinal administration of Endostatin

Objective Endostatin is an endogeneous angiogenesis inhibitor. The purpose of this study was to investigated the effect of Endostatin on the eyes of rats with experimential choroidal neovascularization (CNV). Methods Experimental CNV was induced by laser photocoagulation. Animals were given subretinal injections of recombinant human Endostatin 20 μl(5 g/L) or 0.9% chlorine sodium . The intensity of fluorescein leakage from the photocoagulated lesions was studied 13days after photocoagulation. The area of CNV at each rupture site was measured using high molecular weight FITC-dextran (MW 2×10 6)for high resolution angiography in RPE-choroid-sclera flat mounts.In addition,8 eyes in each group were removed and fixed 14 days after photocoagulation,cut into thin sections. The sections were examined by light microscopy. Immunolocalization of Endoglin(CD105) and factor Ⅷ on sections of CNV lesions was studied by immunohistochemical evaluation. Results After Endostatin injection,fluorescein leakage from the CNV lesions decreased significantly compared with the control eyes. The average area of CNV at sites of the Bruch′s membrane rupture showed significant difference in eyes injected with Endostatin compared with control eyes .Endothelial cells demonstrated strong immunoreactivity of CD105 and factor Ⅷ in CNV lesions of control eyes. CD105-positive cell were not detected in normal chorioretinal tissues. Conclusions The development of CNV can be inhibited by injection of Endostatin,which suggest that Endostatin may be benefical in treating CNV and that further studies can be considered to evaluate this possibility.(Chin J Ophthalmol,2004,40:266-271)