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Objective: corneal alkali burn angiogenesis mechanisms and drug treatment has been research focus, vascular endothelial growth factor (VEGF) has been shown to play a central role in corneal neovascularization process. In recent years, studies have shown that hepatocyte growth factor (HGF) is a strong and promote nascent vascular growth factor, and low molecular weight heparin (LMWH) inhibit angiogenesis, but the the HGF and corneal neovascularization relationship and LMWH inhibit corneal neovascularization few reports of vascular research at home and abroad. The experiment by alkali burns prepared rat corneal neovascularization model, measuring the protein and mRNA expression of HGF and VEGF in corneal alkali burn time, observed LMWH inhibition of corneal neovascularization and to explore topical ocular application LMWH inhibit corneal neovascularization mechanism of action. Methods: 48 healthy Wistar rats, eight randomly selected for the normal group, the remaining 40 Preparation of alkali burn model of corneal neovascularization, and randomly divided into a treatment group and a control group of 20 each. Treatment group 0.5IU / g daily subconjunctival injection of LMWH, and the corresponding amount of saline control group daily subconjunctival injection and continuous infusion for 7 days. Observed under a slit lamp microscope corneal neovascularization, and recorded with a digital camera photography measurement after injury 1d, 4d, 7d, 14d corneal neovascularization area and killed two of the normal group, and the remaining two groups of five randomly selected rats decapitated were killed, the removal of the right cornea, nasal 1/2 cornea fixed in 4% paraformaldehyde solution for HE and immunohistochemical detection of HGF and VEGF protein expression, the temporal side of 1/2 of the cornea is fixed at a low temperature (- 70 ° C) to save for reverse transcription-polymerase chain reaction (RT-PCR) detection of HGF and VEGF mRNA expression. The experimental data SPSS13.0 statistical software for analysis. Results: 1 slit lamp microscope: saline group after injury 1d filling visible corneal edema, limbal vascular network; the first 2d limbal neovascularization; first 7d peaked, the dense corneal neovascularization wide range, covering the entire cornea; diminished the Rule 14d corneal neovascularization. Low molecular weight heparin group after injury lighter 1d corneal edema, limbal vascular network filling the lighter section 2d limbal no neovascularization, 4d, 7d corneal vascular sparse than the untreated group, the 14d vascular decline than untreated group significantly. 2 corneal neovascularization area statistics: alkali burns after the first day, the saline group and the LMWH group had no neovascularization. After injury, 4d, 7d, 14d, saline group corneal neovascularization area (mm2) were 15.10 ± 0.18,28.82 ± 0.37,39.45 ± 0.45, and LMWH group were 12.36 ± 1.12,21.50 ± 1.68,35.01 ± 1.64, after injury, 4d, 7d, 14d LMWH group of corneal neovascularization vascular area than in the saline group, the difference was statistically significant. (Section 4d t = 4.281, P lt; 0.05; the first 7d t = 9.504, P lt; 0.01; Section 14d t = 5.808, P lt; 0.01). 3 corneal tissue HGF and VEGF immunohistochemical staining 3.1 cornea HGF protein: HGF in normal rat small amount of expression of the corneal epithelium, were first 1,4,7,14 d, saline group corneal the HGF surface density value after alkali burns 0.3199 ± 0.0092,0.6973 ± 0.0102,0.5071 ± 0.0101,0.3940 ± 0.0540, the LMWH group of VEGF surface density values ??were 0.2950 ± 0.0054,0.4838 ± 0.0102,0.3713 ± 0.0059,0.3497 ± 0.0137. Injury after 1d, 4d, 7d, 14d, saline group and the LMWH group difference was statistically significant (P lt; 0.05). 3.2 corneal VEGF protein expression: normal rat cornea no VEGF staining positive alkali burns 1,4,7,14 saline group corneal VEGF surface density values ??were .3506 ± 0.0077,0.8746 ± 0.0109,0.5928 ± 0.0910 , 0.4477 ± 0.0355. LMWH group corneal VEGF surface density values ??were 0.3158 ± 0.055,0.6748 ± 0.0960,0.3970 ± 0.0084,0.3371 ± 0.04208. Injury after 1d, 4d, 7d, 14d, saline group and the LMWH group difference was statistically significant (P lt; 0.05). The 4.1 HGF mRNA by RT-PCR, the 4 corneal HGF and VEGF expression of love: HGF mRNA little expression in normal corneal tissue, 1,4,7,14 saline group corneal alkali burns the HGF optical density values ??were 30.94 ± 2.70,78.08 ± 3.06,65.67 ± 0.48,28.62 ± 4.90, LMWH group corneal HGF optical density values ??were 25.20 ± 1.02,49.25 ± 4.60,40.20 ± 1.82,23.05 ± 4.80. Hurt 1,4,7,14 HGF optical density value of the LMWH group compared with the saline group significantly reduced, the difference was significant (P lt; 0.01). 4.2 VEGF mRNA expression: no expression of VEGF mRNA in the normal cornea. Alkali burns 1,4,7,14 saline group corneal VEGF optical density values ??were 40.46 ± 3.26,88.26 ± 2.90,68.80 ± 5.40,42.68 ± 2.64 optical density value of the LMWH group of VEGF were 31.20 ± 1.92,60.49 ± 4.60,54.68 ± 1.80,38.08 ± 0.86. The 4th day after injury, VEGF optical density value of the LMWH group compared with the saline group significantly reduced, the difference was statistically significant (P lt; 0.01), between 7 and 14 days, the LMWH group and the saline group difference was statistically significant ( P lt; 0.05). Conclusion: 1 HGF and VEGF involved in the formation of corneal neovascularization after alkali burn and play an important role in the formation process of CNV. HGF and VEGF in the the the high corneal tissue expression, and expression of the equilibrium concentration destruction promotion of corneal neovascularization. 3 LMWH through antithrombotic and inhibit the formation of fibrin to inhibit the activation of vascular endothelial cells of blood clots and fibrin, reduce alkali burn corneal HGF and VEGF expression and migration of vascular endothelial cells and vascular lumen formation, thus inhibiting CNV generation. 4 LMWH inhibit corneal neovascularization after alkali burn and has good prospects for clinical application.
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