大鼠创伤性脑损伤后海马细胞凋亡及bcl-2、NGF-R阳性细胞的变化

Cells Apoptosis and Changes of bcl-2,NGF-R Positive cells after Traumatic Brain Injury in Rats

目的 :探讨大鼠创伤性脑损伤后不同时相海马细胞凋亡及bcl- 2、NGF -R阳性细胞的变化规律。方法 :采用大鼠自由落体脑损伤模型 ,伤后 1、2、3、4、5、7、10d取脑切片 ,作Nissl染色 ,用TUNEL法检测细胞凋亡 ,免疫组化染色观察bcl-2、NGF-R阳性细胞。结果 :Nissl染色可见损伤侧海马CA2、CA3区锥体细胞层细胞消失或排列紊乱。损伤侧海马凋亡细胞伤后 5d达到高峰 ,正常侧海马各时相点均未见到凋亡细胞。损伤侧海马bcl - 2阳性细胞数量下降 ,伤后 3d至最低点 ;NGF -R阳性细胞数量增加 ,伤后 5d达到高峰。结论 :大鼠创伤性脑损伤后损伤侧海马细胞凋亡数量的变化与伤后时程有关。伤后细胞bcl-2表达下降。

Objective:To explore cells apoptosis and bcl-2,NGF-R positive cells changes in hippocampus at different time after traumatic brain injury(TBI).Methods:TBI rat models were made by Feeney’s method.Nissl staining,TUNEL and immunohistochemistry of bcl-2 and NGF-R were employed at 1,2,3,4,5,7 and 10 days after TBI.Results:The pyramidal neurons in hippocampus CA2 and CA3 region were lost or disorganized in Nissl staining slices.TUNEL positive cells reached the maximum level 5 days later in ipsilateral hippocampus.TUNEL positive cells were not found in contralateral hippocampus.The bcl-2 positive cells decreased in the ipsilateral hippocampus and reached the lowest level 3 days later.NGF-R positive cells increased in ipsilateral hippocampus and reached the maximum level 5 days later.Conclusion:The changes of the number of apoptotic cells are associated with temporal course of TBI.The decrease of bcl-2 and the increase of NGF-R expression may be the factors inducing cells apoptosis.