弥漫性脑损伤大鼠血脑屏障及损伤区皮质咬合蛋白表达的变化

目的观察弥漫性脑损伤大鼠脑水肿、血脑屏障通透性及损伤区咬合蛋白表达的变化。方法 SD成年雄性大鼠160只,按随机数字表法分为对照组(n=60)、模型组(n=100)。应用Marmarou方法建立弥漫性脑损伤大鼠模型。各组分别于术后3、12、24、72、168 h行干湿质量法检测2组大鼠脑组织含水量变化,伊文思兰渗出法检测大鼠血脑屏障通透性变化,免疫组化和Western blot检测损伤区周围皮质咬合蛋白表达水平,并对各结果进行相关性分析。结果与对照组比较,模型组各时间点大鼠脑组织含水量明显增加,血脑屏障通透性增高,脑组织损伤区周围皮质咬合蛋白表达明显降低(P<0.05)。脑组织含水量与血脑屏障通透性呈正相关(r=0.734,P<0.05),而与咬合蛋白免疫组化、Western blot表达呈负相关(r=-0.904,r=-0.966,P<0.05),血脑屏障通透性变化与免疫组化,Western blot咬合蛋白表达呈负相关(r=-0.741,r=-0.833,P<0.05)。结论弥漫性脑损伤发生后损伤区皮质咬合蛋白含量明显降低,血脑屏障通透性增高,脑水肿形成。咬合蛋白表达的减少可导致血脑屏障的破坏和脑水肿的形成。

The changes of blood brain barrier and the expression of occludin following traumatic brain injury

Objective To observe the changes of brain edema,blood brain barrier and the expression of occludin following traumatic brain injury.Methods 160 Sprague-Dawley male rats were randomly divided into control group（n=60） and model group（n=100）.Then establish the model of diffuse traumatic brain injury based on the Marmarou＇s method.After injury 3h,12h,24h,72h and 168h,brain water content was measured to observe the changes of the brain edema,the blood brain barrier permeability was marked with Evans blue,and the immunohistochemistry and Western blot were done to observe the expression of occludin around the injury area.Correlation analysis was performed.Results Compared with the control group：the brain water content of the model group was increased more obviously,the Evans blue contents increased, and the content of occludin around the injury area was increased（P0.05）.The changes of brain water content and the blood brain barrier permeability were positively correlated（r=0.734,P0.05）.The changes of brain water content and the expression of occludin were negatively correlated（r=-0.904,r=-0.966,P0.05）.The changes of blood brain barrier permeability and the expression of occludin were negatively correlated（r=-0.741,r=-0.833,P0.05）.Conclusion After the diffuse traumatic brain injury,the expression of occludin around injury area was decreased.The blood brain barrier was damaged.And the brain edema was appeared.The damaging of occludin lead to the increasing of the blood brain barrier permeability and the brain edema.