大鼠创伤性脑损伤后细胞凋亡及NOS阳性细胞的变化

目的：探讨大鼠创伤性脑损伤后不同时相皮质、海马、隔区细胞凋亡及NOS、ChAT阳性细胞的变化。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，经Nissl染色，用TUNEL法检测细胞凋亡，NADPH—d组化染色观察NOS阳性细胞，ChAT免疫组化染色观察隔区ChAT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紊乱。损伤区周围皮质凋亡细胞伤后3d达到高峰；损伤侧海马凋亡细胞伤后5d达到高峰；损伤侧隔区凋亡细胞7d达到高峰。正常侧上述脑区各时相点均未见到凋亡细胞。损伤区周围皮质、损伤侧海马和隔区iNOS阳性细胞数量明显增加。损伤侧隔区ChAT阳性神经元也明显减少。结论：大鼠创伤性脑损伤后损伤区周围皮质和损伤侧海马、隔区细胞凋亡数量的变化与伤后时程有关。伤后细胞iNOS表达增加是导致细胞凋亡的因素。

Cell apoptosis and changes of NOS positive cells after traumatic brain injury in rats

Objective: To explore cell apoptosis and NOS, ChAT positive neurons changes in cortex, hippocampus and septal region at different time after traumatic brain injury (TBI). Methods: TBI rat models were made by Feeney's method. Nissl staining, TUNEL and immunohistochemistry of ChAT were employed and NOS positive cells were dyed by NADPH-d histochemistry at 1, 2, 3, 4, 5, 7 and 10 days after TBI. Results: The pyramidal neurons in hippocampus CA2 and CA3 region lost or disorganized in Nissl staining slices. TUNEL positive cells reached a peak at the 3rd day after injury in ipsilateral injury cortex. TUNEL positive cells reached maximum level 5 days later in ipsilateral hippocampus. TUNEL positive cells reached a peak 7 days after injury. TUNEL positive cells were not found in contralateral cortex , hippocampus and septal region. iNOS positive cells increased in ipsilateral cortex, hippocampus and septal region. The ChAT positive neurons decreased in the ipsilateral septal region. Conclusions: The changes of the number of apoptotic cells are associated with temporal course of TBI. The increasing of iNOS expression is the reasons for inducing cell apoptosis.