全脑照射后血脑屏障改变对放射性脑损伤的影响  

The study on the relationship between permeability alteration of blood brain barrier and radiation brain injury after whole brain irradiation in rats

作　　者：阮林[1] 韦力[2] 廉春蓉[2] 张文佳[2] 莫立根[3] 李小妹[3] 

机构地区：[1]广西医科大学第一附属医院放疗科,南宁530021 [2]广西医科大学解剖学教研室 [3]广西医科大学肿瘤医院头颈外科

出　　处：《中国神经精神疾病杂志》2011年第10期591-595,共5页Chinese Journal of Nervous and Mental Diseases

基　　金：广西青年基金项目(编号:0640038);广西科学基金项目(编号:0342038)

摘　　要：目的探讨全脑照射后血脑屏障通透性的改变对放射性脑损伤的影响。方法 80只昆明小鼠随机分对照组、5 Gy、15 Gy和30 Gy剂量组,每组20只,分别于照射后1周和4周,各组随机取出10只小鼠采用Morris水迷宫测试其空间记忆能力,行为测试结束后,随机抽取7只测量其脑内伊文思蓝的含量,3只在电镜下观察血脑屏障结构的改变。结果照射后1周,15 Gy和30 Gy剂量组脑内依文思蓝明显升高;照射后4周,15 Gy剂量组恢复到对照组水平,而30 Gy剂量组仍未见恢复。照射后1周,15 Gy和30 Gy剂量组小鼠第1次穿越平台的时间延长和穿越次数明显减少;照射后4周,15 Gy剂量组恢复到对照组水平,而30 Gy剂量组仍未见恢复。电镜结果显示15 Gy剂量组照射后1周血脑屏障基膜周围出现透亮区,照射后4周恢复;30 Gy剂量组照射后1周血脑屏障基膜周围也出现透亮区,而照射后4周除血脑屏障基膜继续透亮区外,尚出现内皮细胞核固缩、神经元凋亡和脱髓鞘等现象。结论放射后血脑屏障的通透性的改变是放射损伤的结果,可能也是放射后继发性脑损伤的原因。Objective To observe the effects of the changes of blood brain-barrier on radiation encephalophathy after whole brain irradiation. Methods Eighty mice were randomly divided into 4 groups： control group, 5Gy-irradi- ated group, 15Gy-irradiated group and 30Gy-irradiated group （20 mice in each group）. The ability of space memory was tested by using Morris Water Maze in 1 week and 4 weeks after irradiation respectively. The BBB permeability was evaluated by measuring the Evans Blue （EB） content of the brain and the ultrastructural changes of BBB was investi- gated under transmission electron microscope. Results One week after irradiation, the levels of brain EB were signif- icantly higher in 15 and 30 Gy dose groups than in control group. Four weeks later, the levels of brain EB returned to control levels in 15 Gy group but remained unchanged in 30 Gy group. Similarly, the time for first platform cross was prolonged and the number of platform cross was reduced in 15 and 30 Gy groups one week after irradiation, the time for first platform cross and the number of platform cross returned to normal in 15 Gy group but remained unchanged in 30 Gy group four weeks after irradiation. Electron microscopy showed the translucent zone around the basement mem- brane of BBB in 15 and 30 Gy groups. The translucent zone returned to normal in 15 Gy group but still remained ac- companying with endothelial cell shrinkage, neuronal apoptosis and demyelination in 30 Gy group. Conclusions The alteration of BBB permeability after radiation change may result from primary radiation injury or may be the cause of secondary radiation-induced brain injury.

关 键 词：放射性脑损伤 血脑屏障 伊文思蓝 超微结构 

分 类 号：R818[医药卫生—放射医学]