血管内皮生长因子在高原暴露下血脑屏障通透性改变中的作用及其与脑水肿的关系

Role of vascular endothelial growth factor in the changes of permeability of blood-brain barrier and its relationship with cerebral edema in high altitude

目的:探讨血管内皮生长因子(VEGF)在高原暴露下血脑屏障(BBB)通透性改变中的作用及与脑水肿的关系。方法:将大鼠暴露于高原不同海拔下,应用RT-PCR测定脑组织内VEGFmRNA转录水平和双抗体夹心ELISA法测定脑内VEGF蛋白含量,应用比色法测定伊文思蓝(EB)的透过率以确定BBB通透性的变化,脑湿干比重法测定脑含水量百分率。结果:高原暴露下,大鼠脑内VEGF和VEGFmRNA的表达随着海拔增高而增高,随着时间延长而增高,以暴露于5 000 m的特高海拔区第9天增高最明显。与此同时,脑内EB含量和脑内含水量增高。脑内VEGF活性与脑内EB含量和脑含水量之间明显相关。结论:VEGF是高原环境下BBB通透性增高的重要因素。

Objective：To investigate the role of vascular endothelial growth factor（VEGF） in the changes ofpermeability of blood - brain barrier （ BBB ） and its relationship with cerebral edema in high altitude. Methods：Wistar rats were exposed to different altitudes. RT - PCR and the double antibody sandwich ELISA were conductedto detect the transcriptional level and protein level of VEGF respectively in brain tissue homogenate. Colorimetrywas used to determine the amount of Evans blue （ EB ） passing through BBB. The water content in the brain （ WCB ）was measured by the ratio of wet weight to dry weight （W/D）. Results： The protein and mRNA levels of VEGF inbrain increased with the increasing of altitude and prolonging of exposure. The highest levels were obtained at the altitude of 5000m after staying for 9 days. Simultaneously, EB content and WCB showed the same change trends. VEGF expression, EB content and WCB were highly related. Concluion： VEGF is one of the critical inducing factors in the changes of permeability of BBB in high altitude.