大鼠去骨瓣减压术后水孔蛋白-4表达变化的实验研究

目的：研究去骨瓣减压术对大鼠创伤性脑损伤后脑水肿、水孔蛋白-4（AQP-4）表达的影响。方法：应用改良Feeney’s自由落体脑损伤打击装置制成大鼠创伤性脑损伤模型,分为假手术组（SO组）、对照组（C组）及去骨瓣减压组（DC组）,各组在损伤后再分为6、12、24、72、120 h及168 h等6个时间点断头取脑损伤区组织。分别利用干湿重量法测量脑组织含水量和Western-Blot检测AQP-4蛋白的表达。结果：大鼠去骨瓣减压组脑组织含水量及AQP-4蛋白表达呈现先升高后降低的趋势,于伤后24 h达高峰后逐渐下降。与C组相比,上述指标含量均有所下降：脑组织含水量在24、120、168 h差异有统计学意义（P〈0.05）,72 h差异有高度统计学意义（P〈0.01）;AQP-4蛋白表达在12、120 h时间点有统计学意义（P〈0.05）,24、168 h时有高度统计学意义（P〈0.01）。结论：创伤后大鼠脑组织脑水肿与AQP-4表达上调密切相关;去骨瓣减压术可减轻脑水肿,减缓AQP-4表达。该手术对创伤性脑损伤的保护机制可能与减缓AQP-4蛋白表达,从而减轻脑水肿和继发性脑损伤,保护脑组织有关。

Experiment Research of Decompressive Craniectomy on the Changes of Cerebral AQP-4 Expression in Rats following TBI

Objective： To research the effects of decompressive craniectomy on traumatic brain injury by investigating the changes of brain edema, the expression of AQP-4 in Rats. Method： The experimental TBI model was established by bumpiness of free falling body according to Feeney＇s. Three groups were investigated： sham-operated group （ SO ）, control group （ C ） and decompressive craniectomy group （ DC ） . Decompressive craniectomy was performed at injury side immediately after brain insult. All animals were killed 6, 12, 24, 72, 120, 168 h later. The rat brain tissue of injury side were examined for water content （ wet/dry weight ） and protein expression of AQP-4 （ western blot ） respectively. Result： After TBI, water content of brain tissue and the protein expression of AQP-4 in injury region began to increase after brain insult. They reached summit at 24 h after insult, afterward dropped grdualaly. There was significantly positive correlation between expression of AQP-4 protein and the change of brain water content. Compared with the control group, brain water content and the expression of AQP-4 protein were decreased in the decompressive craniectomy group. Conclusion： The change of AQP-4 protein exression are closely related to 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 the level of brain edema after the brain injury. And decompressive craniectomy has protective effects on traumatic brain injury by the mechanism of decreasing the expression of AQP-4 and thereby alleviating brain edema.