大鼠局灶性脑挫伤后Cdk5的表达变化

Changes of Cdk5 expression after focal brain contusion in rats

目的研究大鼠受到一定钝力打击造成中度脑损伤后,3h至10d脑组织Cdk5的表达规律及法医学意义。方法建立大鼠钝力性局灶性脑挫伤模型,应用免疫组织化学技术和免疫蛋白印迹技术观察脑损伤后不同时间脑组织中Cdk5表达变化。结果正常组、假手术组脑组织有少量Cdk5表达;实验组损伤后3h组、6h组Cdk5表达增高,12h组表达明显升高(P<0.05);在24h达到峰值,3d组、5d组、7d组、10d组逐渐下降,并在7d组、10d组基本降至正常,与正常组、假手术组比较基本无差异性(P>0.05)。结论大鼠钝力性脑挫伤后Cdk5在挫伤脑组织周边区表达量增多,并呈现单峰变化,随时间延长基本降至正常。Cdk5表达变化可为早期脑挫伤时间推断奠定基础,提供新的参考指标。

Objective This study aims to evaluate the changes of Cdk5 expression at the time of 3 hours to10 days after moderate brain injury by blunt force impact in a rat model, and to demonstrate its forensic significance.Methods To establish a rat model of blunt focal brain contusion, and to observe the changes of Cdk5 expressionin brain tissue at different timepoints after brain injury by immunohistochemistry and Western blot. Results A lowexpression level of Cdk5 was observed in the brain tissue of both normal and sham control groups. The expression ofCdk5 increased after 3 and 6 hours, remarkably increased at 12 hours, and reached the maximal level at 24 hours afterfocal brain injury. The Cdk5 level gradually decreased 3 days, 5 days, 7 days, and 10 days and reached the normallevel 7 and 10 days after the injury, with no statistical difference （P〉0.05） compared with the normal and sham controlgroups. Conclusion The expression of Cdk5 increased in the peripheral area of contusion tissue after blunt braininjury in rats, showing single peak change, and dropped to normal level with the time extension. The change of Cdk5expression may provide a new reference index for the prediction of early brain contusion.