角膜碱烧伤后VEGF与新生血管渗漏性的相关性实验研究

Experimental study on correlation of VEGF with corneal neovascular permeability after alkali burn

目的研究大鼠角膜碱烧伤后新生血管渗透率的变化并探讨血管内皮细胞生长常大鼠角膜作为对照。结果正常及碱烧伤后1d、2d、3d、5d、7d、10d大鼠角膜新生血管渗透率依次为0mg.L-1.mm-2,(1.14±0.17)mg.L-1.mm-2,(0.24±0.08)mg.L-1.mm-2,(0.29±0.16)mg.L-1.mm-2,(0.14±0.10)mg.L-1.mm-2,(0.09±0.06)mg.L-1.mm-2和(0.05±0.04)mg.L-1.mm-2;角膜组织中VEGF-RNA水平依次为(1.09±0.31)×106拷贝.μg-1总RNA,(7.01±1.99)×106拷贝.μg-1总RNA,(1.01±0.59)×106拷贝.μg-1总RNA,(2.43±0.43)×106拷贝.μg-1总RNA,(0.99±1.31)×106拷贝.μg-1总RNA,(0.95±0.03)×106拷贝.μg-1总RNA和(0.17±0.15)×106拷贝.μg-1总RNA,其中7d和10d的VEGF-RNA低于正常水平(P7=0.011,P10=0.006)。经Pearson相关分析,新生血管渗透率和VEGF-RNA水平呈正相关改变(r=0.866,P<0.01)。结论VEGF在新生血管渗漏的调节机制中起着重要作用;大鼠角膜碱烧伤后期,新生血管渗漏性增高难以应用VEGF机制进行解释的现象,提示可能存在其他的新生血管渗漏调节机制。

Objective To investigate the changes of neovascular permeability, and explore the effect of vascular endothelial growth factor （VEGF）on it after alkali burn. Methods The rat model of alkali burn induced corneal neovascularization （CNV） was constructed. Neovascular permeability was measured by Evans blue method at 1 day,2 days,3 days,5 days,7 days and 10 days after surgery,respectively. Expression of vascular endothelial growth factor（VEGF） was evaluated using real time PCR. Normal corneas were treated as control group. Results Corneal neovascular permeability rate was （1.14±0. 17）mg · L^-1·mm^-2,（0. 24 ±0.08）mg · L^-1·mm^-2,（0. 29 ±0. 16）mg · L^-1·mm^-2 ,（0. 14 ±0. 10）mg · L^-1·mm^-2, （0.09 ±0.06）mg · L^-1·mm^-2 and （0.05 ± 0.04）mg · L^-1·mm^-2 at 1 day,2 days,3 days,5 days,7 days and 10 days after surgery respectively,whereas normal control was 0 mg · L^-1·mm^-2. The VEGF expression was （7.01 ±1.99） ×10^6 copy· μg^-1 RNA,（1.01 ±0.59） ×10^6 copy· μg^-1 RNA,（2.43 ±0.43） × 10^6 copy · μg^-1 RNA, （0.99 ± 1.31 ） × 10^6 copy· μg^-1RNA, （0.95 ± 0. 03 ） × 10^6 copy · μg^-1RNA and （0.17 ±0. 15） × 10^6 copy · μg^-1 RNA respectively on the above mentioned per time point. The expression of VEGF of corneas at 7 days and 10 days were decreased significantly compared with that of normal corneas, whose expression was （ 1.09 ± 0.31 ） × 10^6 copy · μg^-1 （P7 d = 0.011, P10 d = 0.006 ）. The correlation coefficiency between VEGF and neovascular permeability rate was 0. 855 （P 〈 0.01 ）. Conclusions VEGF plays a key role in regulating the neovascular permeability after alkali burn. Whereas at the late stage of alkali burn, it is difficult to explain the neovascular hyper permeability with VEGF, which suggests that other factors may have effects on inhibition of neovascular permeability.