虫草素对碱烧伤诱导大鼠角膜新生血管的抑制作用

摘要

Objective:To investigate the inhibit effect of cordycepin on rat corneal neovascularization (CNV) after alkali burn and its influence over expression of VEGF and VEGFR 2.Methods:CNV model was induced by alkali burn of the cornea with 1 mol · L-1NaOH on 48 SD rats.The next day rats were divided with equal number into four groups randomly after modeling:model group accepted 0.1 mL saline,positive control group accepted 0.6mg/kg dexamethasone,high and low dose treatment group accepted 4mg/kg and 2mg/kg cordycepin respectively.4 healthy rats' contralateral eyes were selected as normal control group.On the 4th,8th and 14th day executed the rats to extract cornea.Histological changes were observed after HE staining,mearsuring CNV area,ELISA was adopted to test expression of cornea VEGF,SP was adopted to test expression of VEGFR 2.Results:Compared with the model group,right eye cornea burned area showed grey and white nubecula;comparing with normal control group,CNV was observed in cornea of all groups,indicating successful modeling;comparing with normal control group,CNV area was relatively small in high dose group and 8th day after modeling in low dose group,expression of VEGF and VEGFR 2 in high dose corneal tissue,differences were statistical significant (P ＜ O.05);comparing with high dose group,low dose group showed bigger CNV are,VEGF and VEGFR 2 showed more expression,differences were statistical significant (P ＜ 0.05).Conclusion:Large dose of cordycepin can inhibit the growth of CNV induced by alkali burn in rat cornea,the mechanism might be relevant with cordycepin inhibited VEGF expression in burned corneal tissue.%目的:研究虫草素对大鼠角膜新生血管的作用及其对角膜组织血管内皮生长因子(VEGF)和其受体VEGFR2表达的影响.方法:48只SD大鼠右眼采用1 moL/L氢氧化钠(NaOH)角膜贴纸方法灼伤角膜制备角膜新生血管模型,造模后隔日随机给予生理盐水0.1 mL(模型对照组)、地塞米松0.6 mg/kg(阳性对照组)、虫草素4 mg/kg(高剂量组)、虫草素2 mg/k(低剂量组)球结膜下注射,每组12只,另取4只未造模大鼠对侧健康眼球为正常对照组;于造模成功后第4、8及14天时分次处死大鼠取角膜组织,HE染色观察各组大鼠角膜组织学改变,测量各组角膜新生血管面积,夹心法ELISA检测角膜VEGF的表达,SP法检测VEGFR2的表达.结果:48只模型大鼠右眼角膜烧灼区域呈灰白色混浊,与正常对照组比较,造模后各组角膜均有新生血管生成,提示造模成功;与正常对照组比较,高剂量组和造模第8天后的低剂量组角膜新生血管生长面积较小,高剂量组角膜组织中VEGF、VEGFR2表达减少,差异具有统计学意义(P＜0.05);与高剂量组比较,低剂量组角膜新生血管生长面积更大,且VEGF、VEGFR2表达较多,差异具有统计学意义(P＜0.05).结论:较大剂量虫草素能有效抑制NaOH所致大鼠角膜新生血管的形成,其机制可能与虫草素抑制灼伤角膜组织中VEGF表达有关.