微泡造影剂介导的声空效应对胶质瘤大鼠血脑屏障通透性及替莫唑胺疗效的影响

摘要

目的 观察微泡造影剂联合超声对胶质瘤大鼠血脑屏障通透性及化疗药物疗效的影响.方法 通过透射电镜观察超微结构、Western blotting检测紧密连接蛋白claudin-5的表达、脑组织伊文蓝染色检测并确认影响Wistar大鼠血脑屏障通透性的最佳造影剂浓度及最佳超声模式.采用大鼠胶质瘤细胞系9L脑纹状体注射建立Wistar大鼠胶质瘤模型,予以替莫唑胺化疗(50mg/kg,连用5d)后,计算瘤体大小,ELISA检测血清中肿瘤标志物胶质纤维酸性蛋白(GFAP)的浓度.结果 微泡造影剂联合超声可使血脑屏障内皮细胞间的连接松弛,最佳造影剂浓度为1ml/kg,最佳超声模式为间隙触发(间隙400ms)10min;声空效应组大鼠中伊文蓝通过血脑屏障的含量明显多于对照组(P＜0.05).替莫唑胺化疗后,声空效应组肿瘤体积明显低于对照组,而血清G FAP浓度明显高于对照组(P＜0.05).结论 微泡造影剂联合超声可提高胶质瘤大鼠血脑屏障通透性及化疗药物的疗效.%Objective This research examined the effect ofmicrobubble contrast agent plus ultrasound on the permeability of blood-brain barrier,and explored whether it affects the efficacy of chemotherapeutic drugs on cerebral glioblastoma.Methods Wistar rats were divided into three groups to find the optimal concentration of ultrasonic contrast agent.To identify the best ultrasound mode that affected the permeability of blood brain barrier,we employed transmission electron microscopy for study of brain ultrastructure.Western blotting was used to detect the tight junction protein claudin-5.Evans blue staining of brain tissues was utilized to identify the best ultrasonic contrast agent concentration and mode.Rat glioma cells (line 9L) were injected into Wistar rats.After temozolomide chemotherapy,the tumor size was measured and the tumor marker GFAP in serum was detected by ELISA.Results The best contrast agent concentration which increases permeability of BBB in rats was found to be lml/kg and the best ultrasound mode was intermittentlytriggered pulses lasting for 10min (with interval was set at 400ms).More Evans blue passed the blood-brain barrier in ultrasonic cavitation effect group than in control group (P＜0.05).After temozolomide chemotherapy,more tumor marker GFAP was detected in ultrasonic cavitation effect group than in control group (P＜0.05).Conclusion The permeability of BBB was increased and more temozolomide went through BBB when the rats were subjected to intermittently triggered ultrasonic pulses and were injected at contrast agent at lml/kg,which could help to achieve better therapeutic efficacy for glioblastoma.