创伤性脑损伤后细胞凋亡的时相性研究

目的探讨创伤性脑损伤中细胞凋亡的发生发展过程,为脑损伤后的神经系统保护提供实验资料以及为法医学损伤经过时间推断提供帮助。方法以Feeney自由落体脑损伤大鼠模型为对象,采用DNA缺口末端标记法（TUNEL）染色观察不同损伤时间时脑损伤组脑组织、假手术对照组脑组织和正常对照组脑组织中细胞凋亡的情况。结果创伤性脑损伤后2h即可在伤侧皮层以及同侧的海马区可见细胞凋亡发生,随着损伤经过时间的延长,凋亡细胞逐渐增多,在48~72h凋亡达到高峰,随之逐渐减少,至7d时凋亡数仍显著高于正常对照组和假手术组,正常对照组和假手术组在伤侧对应区和海马区仅偶见凋亡细胞。结论检测损伤区凋亡细胞数对损伤经过时间的推断有重要价值,为法医学损伤诊断起重要作用。

The time-course study of apoptotic cell death after experimental traumatic brain injury in the rat

Objective To search sensitive, reliable and objective marker for estimating the age of wounds in traumatic brain injury, hence the time-course of neuronal apoptosis was investigated following the traumatic brain injury in a rat model. Methods The traumatic brain injury model was established using a modified Feeney method. Wistar rats were randomly divided into cortical impact injury groups, shame operated control group and normal control group. The neuronal apoptosis was observed at 1 h, 2 h, 5 h, 8 h, 12 h, 24 h, 48 h, 72 h, 5d and 7d respectively by TUNEL staining following traumatic brain injury. The shame operated control group was accomplished without cortical impact injury and the other processes the same as the cortical impact injury groups. Results 2 h after traumatic brain injury, the apoptotic cell death was observed at the injury side of cortex and ipsilateral hippocampus region. With the extension of injury time, the apoptotic cell index gradually increased and reached its apex during 48~72 h after traumatic brain injury and then gradually decreased. And the number of apoptotic cells was still significantly higher than the shame operated control group and normal control group at 7 d. Conclusions The apoptotic cell index may be helpful for estimating the age of wounds following traumatic brain injury and play an important role in forensic medicine practices.