摘要
目的探讨水通道蛋白-4(AQP-4)在大鼠创伤性脑水肿中的表达及其对血脑屏障(BBB)通透性的影响。方法按照改进的Feeney自由落体撞击法建立大鼠创伤性脑损伤(TBI)模型,用磁共振成像(MRI)对大鼠脑水肿进行检测,干/湿比重法和伊文思蓝(EB)测定法观察大鼠TBI后不同时相脑组织含水量和BBB通透性的变化,并采用逆转录聚合酶链反应(RT-PCR)法检测AQP-4 mRNA的表达,蛋白质免疫印迹(Western blot)法检测AQP-4蛋白的表达。结果TBI后MRI表现为T1WI的低信号或等信号、T2WI高信号。TBI后4h伤区脑组织含水量及EB含量开始增多,AQP-4 mRNA、AQP-4蛋白表达开始增高并逐渐上升,24h达到高峰,随后逐渐下降,伤后72h仍维持在较高水平(P<0.05)。AQP-4 mRNA、AQP-4蛋白表达与脑组织的含水量及EB含量呈正相关。结论创伤性脑损伤后早期AQP-4 mRNA、AQP-4蛋白表达的变化与血脑屏障通透性的改变及脑水肿的形成和发展密切相关。可能通过上调水通道蛋白AQP-4的表达,增加血脑屏障的通透性,参与脑水肿的形成。
Objective To investigate the expression level of cerebral aquaporin-4 （AQP-4）and its effect on permeability of blood-brain barrier during traumatic brain injury （TBI） in rats. Methods The experimental TBI model was established by bumpiness of free falling body according to Feeney＇s. The rats＇ cerebral edema were imaged with magnetic resonance image （MRI） ,The changes of brain water content and permeability of blood-brain barrier （BBB） were measured by the methods of wet and dry weight and Evans blue fluorometry. The expression of AQP-4 mRNA was examined by reverse transcriptase polymerase chain reaction （RT-PCR）. The protein expression of AQP-4 was examined by western blot. Results After TBI the MRI performance is the T1WI low signal or the equisignal and the T2WI high signal. 4 h after TBI,water content of brain tissue and EB content in the contusion side significantly increased,the expression of AQP-4 mRNA and the protein expression of AQP-4 in contusion marginal region began to increase. They reached summit at 24 h after operation, afterward dropped gradually,and still maintained at the high level after 72 h （P 〈 0. 05 ）. There was significantly positive correlation between expression of AQP-4 mRNA, protein expression of AQP4 and change of EB content. Conclusions The change of AQP-4 mRNA and AQP-4 protein expression are closely related to the destruction of BBB and the formation and development of brain edema during the early stage after traumatic brain injury. The early up-regulated expression of AQP-4 may increase permeability of blood-brain barrier,which is concerned with the development of brain edema after the brain injury.
出处
《中华临床医师杂志（电子版）》
CAS
2009年第5期38-42,共5页
Chinese Journal of Clinicians(Electronic Edition)
基金
辽宁省教育厅高等学校科研基金资助项目(05L110)
