摘要
目的探讨放射线全脑常规外照射后对血脑屏障通透性的影响,为临床颅内肿瘤放化疗的序贯性和最佳化疗时机提供理论基础。方法100只正常成熟Sprague Dawley大鼠被随机分为0、10、20、30、40Gy组,每组20只。采用60Coγ线进行全脑常规分割外照射,2Gy/次,1个野/d,5次/周。各组完成计划照射剂量后16h经尾静脉注射氨甲蝶呤(MTX)25mg/kg,2h后采集静脉血及脑脊液,用RP HPLC法监测其中的MTX浓度。结果对照组、10、20、30、40Gy组脑脊液中MTX平均浓度分别为0.07、0.08、0.12、0.24、0.23mg/L。经秩变换检验方差分析,10Gy组与对照组、30Gy与40Gy组脑脊液中MTX浓度比较差异无统计学意义(P>0.05),其余各组间两两比较差异均有统计学意义(P值均<0.05)。血液中MTX平均浓度各组比较均无统计学意义(P>0.05)结论放射线具有降低血脑屏障功能的作用,照射20～30Gy其通透性明显增加,故20～30Gy时为化疗最佳时机。
Objective To explore the effect of drug permeability in rat blood-brain barrier（BBB） after different doses of whole brain conventional fractionafion irradiation in rats and provide the experimental basis for the optimum time of clinical chemotherapy, Methods According to different irradiation doses, 100 adult SpragueDowley rats were divided randomly into 5 groups： the normal control group （0 Gy ） ; 10 Gy;20 Gy;30 Gy; and 40 Gy group. All rats were exposed to conventional fractionation（2 Gy/d, 5 d/w） with 60^Co γ-ray. MTX（25 mg/kg） was injected through the tail mainline 16 hours after whole brain irradiation. Cerebrospinal fluid（CSF） and blood were collected 2 hours later. Those samples were used to assay MTX concentration using RP-HPLC. Results MTX mean concentrations in CSF was 0.07,0.08,0.12,0.24,0.23 mg/L in the control, 10 Gy,20 Gy,30 Gy, 40 Gy groups, respectively. All the data was analyzed with rank test of transform. MTX concentration of CSF was significantly different except the control and 10 Gy,30 Gy and 40 Gy group. MTX concentration of blood was not significantly different in all groups （ P 〉 0.05）. Conclusions Irradiation can directly damage the function of BBB. BBB would be opened gradually following the increase of irradiation dose. It could be considered as the optimum time of chemotherapy when the whole brain irradiation ranges from 20 Gy to 30 Gy.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2006年第3期229-232,共4页
Chinese Journal of Radiation Oncology
基金
江苏省教育厅基金资助(H200534)
江苏省教育厅自然科学基金资助项目(01KJD320033)
关键词
颅脑照射
Γ射线
血脑屏障
氨甲蝶呤
大鼠
Cranial irradiation
Gamma rays
Blood-brain barrier
Methotrexate
Rats
