VEGF和IGF-1在代谢性酸中毒诱导的新生大鼠视网膜细胞中的表达

Expression of VEGF and IGF-1 in rats model of acidosis-induced retinopathy

目的了解代谢性酸中毒诱导新生大鼠视网膜病变的发展进程,探讨其发生与血管内皮生长因子(VEGF)和胰岛素样细胞生长因子-1(IGF-1)的关系。方法模型组新生Sprague-Daw ley大鼠80只,从出生后第2天开始按535 mg.kg-1的剂量管饲NH4C l(质量浓度为50 mg.m l-1),每天2次,连续7 d,然后进入恢复期;另选未行管饲的80只新生大鼠作为对照组。两组大鼠分别于出生后第3、5、8、10、13、20天处死。取出双眼进行视网膜铺片和二磷酸腺苷酶染色,对视网膜血管进行评估;视网膜切片经常规HE染色定量反映视网膜血管增生情况;用免疫组化方法进行VEGF和IGF-1测定。结果模型组大鼠在出生后第3、5、8、10、13、20天新生血管(NV)发生率分别为0、7%、24%、59%、23%、0。HE染色可见实验组10 d龄鼠有较多突破视网膜内界膜的血管内皮细胞核,平均每张切片有(14.67±2.16)个。而对照组未见或极少见突破内界膜的血管内皮细胞核,每张仅(0.87±0.75)个,两者比较差异有统计学意义(t=18.47,P<0.000 1)。出生后第10、13天,模型组鼠VEGF的蛋白水平比对照组明显升高,差异有统计学意义(P<0.05)。出生后第8天,模型组大鼠视网膜IGF-1的蛋白水平比对照组明显下降,差异有统计学意义(P<0.05)。结论代谢性酸中毒可能损害了正在发育的视网膜血管而引起新生血管;视网膜新生血管的发生与VEGF和IGF-1的异常表达有关。

Objective To analyze the expression and significance of vascular endothelial growth factor （VEGF） and insulin-like growth factor-1 （IGF-1）in rats model of acidosis-induced retinopathy,and to elucidate the action of VEGF and IGF-1 in the process of neovascularization in retinopathy of prematurity（ROP）. Methods A total of 80 newborn Sprague-Dawley rats in experimental group underwent tubal feeding of NH4CI（535 mg·kg^-1 ） with the concentration of （50mg·kg^-1 ） （ twice per day） from the second day after the birth for 7 days and followed by a period of recovery. Additional 80 neonatal rats were in the control group without the tubal feeding. The rats were executed at the 3rd,Sth,8th, 10th, 13th,20th day after birth respectively. The retinal vessels were evaluated through retinal tretched preparation and adenosine diphosphatase （ADPase） staining. The newborn vessels were quantified by HE staining. VEGF and IGF-1 in retina were detected by immunohistochemistry. Results In the experimental group, the incidence of retinal neovascularization（NV） at the 3rd,5th,8th, 10th, 13th,20th day after birth was 0,7% ,24% ,59% ,23% and 0 respectively. In acidosis-induced retinopathy （AIR） group of 10-day old, the number of neovascular nuclei extending into the vireo was 14.67 ± 2.16,and that of the control group was 0.87 ± 0.75, there was significant difference between the two groups （t = 18.47,P 〈0. 000 1 ）. The result of immunohistochemistry revealed that in AIR grope the protein expression of VEGF was stronger than that of the control group on the 10th and 13th day. There was significant difference between the two groups （ P 〈 0.05 ）. The protein of IGF-1 was lower on the 8th day in AIR than that in control group. There was significant difference between the two groups （P 〈0. 05）. Conclusions Metabolic acidosis may induce NV by injuring the developing retinal vessels. Retinal NV induced by acidosis relates to VEGF and IGF-1.