急性弥漫性轴索损伤超微结构及血脑屏障改变的实验研究

Change of blood-brain barrier and axonal ultrastructure after diffuse axonal injury in rats

目的 研究大鼠脑弥漫性轴索损伤后血脑屏障及超微结构在不同时间点的变化情况。 方法 利用角加速度旋转模具制作大鼠急性弥漫性轴索损伤模型 ,在透射电镜下观察硝酸镧颗粒的分布情况和超微形态的改变。 结果 大鼠弥漫性轴索损伤后 30min血脑屏障通透性发生改变 ,2 4h通透性增加达到高峰 ,72h略有下降。超微结构以 72h损害最为严重。 结论 大鼠急性弥漫性轴索损伤后血脑屏障通透性增加是造成脑水肿的主要原因之一。超微结构的改变以广泛细胞肿胀、轴索溶解、断裂、回缩球形成为主要特征。

Objective To study the change of blood-brain barrier(BBB) and axonal ultrastructure at different time points after diffuse axonal injury(DAI). Methods Animal models of DAI were made with an angular acceleration rotating device. The spread of lanthanum nitrate and the change of ultrastructure were observed under a transmission electron microscope. Results The change of BBB was very obvious. The lanthanum nitrate crossed BBB from the brain at 30 min after DAI and reached peak at 24 h. And the ultrastructure was damaged most seriously at 72 h after DAI. Conclusions The damage of BBB is the main factor of brain edema after DAI. The main characteristics of the ultrastructure change are expressed as extensive cell swelling, axon dissolving, axon broken and axon retracting to balls.