雷帕霉素滴眼液对兔角膜新生血管的抑制作用

Inhibition of corneal neovascularization treated with rapamycin eye drops in rabbits

背景:雷帕霉素为抗移植排斥反应的药物,近年来有实验证实雷帕霉素能有效抑制小鼠视网膜及虹膜新生血管。目的:验证新型免疫抑制剂雷帕霉素对碱烧伤诱导兔角膜新生血管的影响,并与地塞米松相比较。设计、时间及地点:随机对照动物实验,于2007-07/2008-02在重庆医科大学基础研究所免疫组织化学实验室及神经病学重点实验室完成。材料:选用健康成年新西兰家兔30只30眼,制作中度碱烧伤诱导的兔角膜新生血管模型。方法:将造模成功的30只兔30眼按随机数字表法分为5组(n=6),即10,20mg/L雷帕霉素组、2.5g/L地塞米松组、雷帕霉素溶媒组及空白对照组,空白对照组不给予任何干预措施,其余各组均于碱烧伤后第2天给予相应药物滴眼,4次/d。主要观察指标:于碱烧伤后第3,7,14天应用显微镜观察各组兔角膜新生血管的长度及面积,用免疫组织化学方法定性观察血管内皮生长因子的表达。结果:①10,20mg/L雷帕霉素组、2.5g/L地塞米松组兔角膜新生血管的长度与面积均小于雷帕霉素溶媒组及空白对照组(P<0.01),其中10,20mg/L雷帕霉素组小于2.5g/L地塞米松组(P<0.05),不同剂量的雷帕霉素组差异不明显。②角膜血管内皮生长因子在10,20mg/L雷帕霉素组及2.5g/L地塞米松组表达减弱,在雷帕霉素溶媒组与空白对照组表达增强。结论:局部滴用10,20mg/L雷帕霉素滴眼液及2.5g/L地塞米松滴眼液均可抑制碱烧伤诱导兔角膜新生血管的生长,雷帕霉素作用强于地塞米松。

BACKGROUND： Rapamycin can resist the graft rejective reaction, and recent studies have proved that rapamycin carries an inhibition effect on the retina and iris neovascularization in rats. OBJECTIVE： To evaluate the effect of immunosuppressant rapamycin on corneal neovascularization （CNV） of the rabbits induced by alkali cauterization, and compare with the effect of dexamethasone. DESIGN, TIME AND SETTING： A randomized control animal experiment was carried out in the Immunohistochemistry Laboratory and Key Laboratory of Neurology, Basic Research Institute of Chongqing Medical University （Chongqing, China） from July 2007 to February 2008. MATERIALS： Thirty healthy adult New Zealand rabbits （30 eyes） were adopted to establish the CNV model induced by moderate alkali cauterization. METHODS： CNV model was successfully induced in 30 rabbits, and then divided into five groups （n=6）： 10 mg/L rapamycin treated group, 20 mg/L rapamycin treated group, 2.5 g/L dexamethasone treated group, rapamycin menstruum group and control group. Except the control group remained untreated, other four groups were treated with eye drops since the 2nd day after alkali injury, 4 times per day. MAIN OUTCOME MEASURES： The length and area of CNV in each group were examined by microscope at days 3, 7 and 14 following the injury. Immunohistochemistry was used to determine the vascular endothelial growth factor level. RESULTS： Both rapamycin and dexamethasone eye drops could inhibit the length and area of CNV in rabbits compared with rapamycin menstruum group and control group （P 〈 0.01）, and the effect of 2.5 g/L dexamethasone was superior to that of 10 and 20 mg/L rapamycin （P 〈 0.05）. However, there was no remarkable difference between the two concentrations of rapamycin eye drops. The expression of vascular endothelial growth factor was suppressed significantly in rapamycin and dexamethasone treated groups, nevertheless the expression was markedly increased in the rapamycin menstruum group and control group. CONCLUSION： Both local application of rapamycin and dexamethasone are effective to inhibit the CNV induced by alkaline burn, and rapamycin appears to be more effective than dexamethasone.