摘要
目的研究不同氧浓度环境对新生大鼠氧视网膜病变新生血管的影响及血管内皮生长因子(VEGF)和色素上皮衍生因子(PEDF)在视网膜血管形成中的作用。方法新生大鼠生后即置于50%和45%～12.5%的氧环境下14d。计数每张切片上突破内界膜且与内界膜有联系的内皮细胞核数,免疫组织化学检测VEGF、PEDF在大鼠视网膜的表达。结果在暴露于45/12.5%氧环境下的大鼠,视网膜新生血管密度为92.62±23.45,持续50%氧组为14.23±12.86,对照组为12.96±10.58;VEGF阳性细胞率在45%～12.5%氧环境组、持续50%氧组分别为57.89%、4.98%,而对照组为13.20%,差异有统计学意义(F=479.461,P=0.000)。离开暴露环境后0、2d的VEGF阳性细胞率在45%～12.5%氧和持续50%氧组分别为(57.89±2.84)%、(39.38±1.10)%和(34.98±4.80)%、(27.80±4.05)%(P均=0.000)。PEDF在三组的表达差异无统计学意义(F=0.271～0.765,P均>0.05)。因此,两实验组病理形态方面差异与视网膜的总VEGF水平相关,而总的PEDF水平在各组间差异无统计学意义。结论在鼠早产儿视网膜病(ROP)模型中,血氧小的波动就可触发随后不成比例的血管增长,后者伴随比PEDF更强烈的VEGF的变化。如果这种变化同样存在,即可解释胎龄、体重、临床相似的早产儿,在相同给氧条件下的部分发生ROP,而部分不发生ROP的现象。
Objectives To study the effects of different concentrations of oxygen on neovascularization in oxygen-induced retinopathy（OIR）of newborn rats. To determine the roles of vascular endothelial growth factor（VEGF）and pigment epithelium-derived factor（PEDF）in vascularization of the developing retina. Methods Fifty-two newborn Sprague-Dawley rats were included in the study. They were divided into three groups：group 1,group 2,and control group. Group 1（18 rats）was exposed to 50% O2 for 14 days and followed by 5 days of room air recovery. Group 2（18 rats）was exposed to cycles of O2（45% ～ 12.5%）for 14 days,followed by 5 days of room air recovery. The control group（16 rats）was raised in air room. The rats were executed on 0,2,and 5 days post exposure. The total number of nuclei counted per retina was defined as the nucleus count. Nuclei above the internal limiting membrane were counted. The retinal levels of VEGF and PEDF expressions were assessed with immunohistochemistry. Results The nucleus counts of the retinas in group 1,group 2,and the control were 14.23 ± 12.86,92.62 ± 23.45,and 12.96 ± 10.58,respectively. VEGF-positive cells were 34.98 ± 4.80 in the group treated with continual period of 50% oxygen,（57.89 ± 2.84）% in the group treated with alternating periods of 45% and 12.5% oxygen, and（13.20 ± 0.38）% in the control. The differences in the VEGF-positive cell among three groups were significant（P = 0.000）,with no diffe- rences in the PEDF. Conclusions This study suggested that a small change in blood oxygen profile could trigger a disproportionate increase in subsequent neovascularization,accompanied by more dramatic changes of retinal VEGF level than PEDF level. If a similar threshold exists in the human,this could explain why some but not all oxygen-treated premature infants develop retinopathy despite similar gestational ages,birth weights and clinical courses.
出处
《临床儿科杂志》
CAS
CSCD
北大核心
2008年第9期772-775,共4页
Journal of Clinical Pediatrics
关键词
血管内皮生长因子
色素上皮衍生因子
视网膜
血管发育
新生大鼠
vascular endothelial growth factor
pigment epithelium-derived factor
retina
vascular development
newborn rat
