Avastin对大鼠角膜新生血管的抑制及超微结构的影响

目的:探讨Avastin对角膜新生血管形成及角膜内血管内皮生长因子(VEGF)的影响及其超微结构的影响。方法:Wistar大鼠96只随机分3组,采用碱烧伤的方法制备大鼠角膜新生血管模型;正常不烧伤组4只。烧伤后隔日球结膜下注射0.1mL生理盐水组32只,烧伤后隔日球结膜下注射Avastin0.1mL组32只,烧伤后隔日球结膜下注射地塞米松0.1mL组32只。碱烧伤术后在裂隙灯显微镜下观察大鼠角膜混浊度;宏观测量新生血管长度;组织病理切片HE染色作微血管计数;透射电镜观察超微结构的改变;免疫组化检测角膜VEGF的蛋白表达情况;CD34标记新生血管,显微镜下微血管计数方法研究角膜新生血管形成及抑制情况。结果:治疗组在3,7,10,14d较对照组角膜混浊程度轻(P<0.05);14d形成的新生血管数量较对照组少(P<0.05)。实验组新生血管微血管数量减少,VEGF蛋白表达下降,具有统计学差异。VEGF主要表达在角膜受损区的感染细胞胞质内,其出现时间与位置与角膜新生血管一致。Avastin和地塞米松均可有效抑制角膜新生血管,减少角膜内VEGF表达,两者无统计学差异,结膜下注射Avastin和地塞米松后,大鼠角膜超微结构无除烧伤后其它显著改变。结论:Avastin和地塞米松可抑制角膜新生血管,减少角膜内VEGF表达,对角膜的超微结构均无显著毒性。

Experimental study on Avastin therapy for neovascularization of the rat cornea and its impact on the ultrastructure

AIM:To explore the Avastin therapy for neovas-cularization of the rat cornea and its impact on the ultrastructure.·METHODS: Established Wistar rats were selected for four groups at random, group 1 (n=4) normal; group 2 (n=32) received a subconjunctival injection of 0.1mL of 9g/L saline solution; group 3 (n=32) received a subconjunctival injection of 2.5mg (0.1mL). Bevacizu-mab; group 4 (n=32) received a subconjunctival injection of 0.1mL dexamethasone. All groups were observed the corneal opacity by slit-lamp microscope at day 3, 7, 10, 14 after corneal alkali burns.neovascularization were evaluated histological after enucleation,fixation with formaldehyde solution,and staining with hematoxylin and eosin(HE).The contents of blood vessel in corneas were measured.Corneal ultrastructural morphology was observed by transmission electron microscope(TEM).The localization and expression of VEGF, CD34 were deter-mined by immunohisto-chemical method.·RESULTS: It was found that corneal opacity was slighter in treatment group than that in control group at day 3,7,10,14 after cautery,which there were statistically significant difference between the treatment group and the control group(P<0.05).From the point of neovas-cularization counted number,the rat corneal neovascula-rization in the treatment group was less than that in the control group at day 14 after alkali burn(P<0.05) with statistically significant difference(P<0.05).The expressions of VEGF, CD34 in normal rats’ cornea were restricted in epithelia and endothelial cell, and VEGF increased gradually at day 3, subsequently the expression decreased slowly after this.There was no difference among Avastin and dexamethasone.·CONCLUSION: Avastin can effectively restrain corneal neovascularization and reduce the corneal opacity.VEGF play important parts in alkali burn of the rat cornea. Avastin therapy may ameliorate corneal alkali burn by effecting with those factors. Avastin therapy for alkali burn is safe andutility.