摘要
目的研究SD大鼠在脑外伤后第1、3、5、10天外周血中CD4+T细胞的变化情况,并尝试从凋亡的角度探讨CD4+T细胞变化的原因。方法参照改进的Feeney氏自由落体硬膜外撞击法制作脑外伤动物模型,在相应的时间点从大鼠心脏取血,通过流式细胞术检查血中CD4+T细胞的数量和代表两条经典凋亡途径上的两个关键酶caspase-8和caspase-9,尝试从凋亡的角度解释CD4+T细胞数量的变化原因。结果从颅脑外伤后第1天,大鼠外周血中CD4+T细胞数量与对照组相比较明显减少(P<0.05),而颅脑外伤后第3天CD4+T细胞数量明显恢复,尽管仍低于对照组,但无统计学意义。CD4+T细胞内的半胱氨酸天冬氨酰蛋白酶-8(caspase-8)和半胱氨酸天冬氨酰蛋白酶-9(caspase-9)分别是两条经典的细胞凋亡途径上的关键蛋白酶,都从颅脑外伤后第1天开始与对照组相比显著下降且有统计学意义(P<0.05),直至颅脑外伤后第10天caspase-8和caspase-9依然较对照组低(P<0.05)。结论颅脑外伤后存在免疫抑制,与CD4+T细胞的数量减少有关。颅脑外伤后外周血中CD4+T细胞数量减少可能不是通过经典的细胞凋亡途径进行的。
Objective To study the changes in CD4＋T cells in the peripheral blood 1, 3,5,10 days after traumatic brain injuries in the SD rats and try to explore the reasons for CD4＋T ceils change from the perspective of apoptosis. Methods Feeney＇s free - fall meth- od was used to produce the epidural impact resulting in the animal model of traumatic brain injury. Rat＇s blood from heart were drawn in the corresponding time duration and the number of CD4 ＋ T cells were checked by flow cytometry. Similarly, the the two key enzymes in the classical apoptotic pathway of caspase - 8 and caspase - 9, i.e. cysteine aspartyl protease - 8 and cysteine aspartyl protease - 9 were also examined to explain the reasons for the changes in the number of CD4＋T ceils from the perspective of apoptosis. Results The CD4＋T cell numbers in the peripheral blood from 1 day after traumatic brain injury in rats were significantly reduced （P 〈 0.05 ） com- pared with the control group. From three days after traumatic brain injury,CD4 ＋ T cell count was significantly restored. However it was still lower than the control group, but not statistically significant. CD4＋T ceils within the cysteine aspartyl protease - 8 （ caspase - 8） and cysteine aspartyl protease - 9 （ caspase - 9） were two key proteases of classic apoptotic pathway which started from 1 day after trau- matic brain injury and they were decreased significantly compared with the control gronp（P 〈 0.05 ）. These enzymes remained relatively low until 10 days after traumatic brain injury（P 〈 0.05）. Conclusion There exists immunosupression as depicted by the decrease in the number of CD4 ＋ T cells after traumatic brain injury. However this decrease in the CD4＋T cells in the peripheral blood may not he carried out by the classical apoptotic pathway.
出处
《医学研究杂志》
2012年第12期136-139,共4页
Journal of Medical Research
