Inhibitory effects of metformin on corneal neovascularization induced by alkali burn in rats / 眼科新进展

ABSTRACT

Objective To investigate the inhibition of metformin on corneal neovascularization in rats following alkali burn.Methods Totally 48 SD rats (48 eyes)were randomly divided into three groups,and they were negative control group (n =6),in which the controls were left untreated,normal saline group(n =21),rats treated with intraperitoneal injection of equivalent saline,and metformin group (n =21),rats subjected to intraperitoneal injection of 120 mg · kg-1 metformin every day.The expression of vascular endothelial growth factor (VEGF),VEGF receptors (Flk1,Flt1) and thrombospondin 1 (TSP1) protein in corneal tissue were detected by Western blot,while RT-PCR was used to detect the expression of VEGF,Flk1,Flt1 and TSP1 mRNA in corneal tissue.Then the morphological structure of cornea was observed by HE staining.Resuits The area of neovascularization in metformin group was smaller than that of the normal saline group on day 5,7,14 after administration (all P ＜0.01).And there was interaction in the both groups with different treatment methods at different time points (F=147.32,P =0.000).The expression of Flk-1 protein in the metformin group was lower than that of the normal saline group,whereas the relative expression of TSP-1 protein was higher than that of the normal saline group (all P ＜ 0.01).The expression of VEGF,Flk-1 and Flt-1 mRNA in the metformin group was lower than those of the normal saline group,but the expression of TSP-1 mRNA was higher than that of the normal saline group (all P ＜0.01).HE staining showed that the degree of corneal edema,the inflammatory response and the number of new blood vessels in the metformin group were significantly alleviated compared with normal saline group.Conclusion Metformin can inhibit the progress of corneal neovascularization in SD rats.