雌激素对大鼠脑创伤后海马区氧应激状态及bax表达的影响

Estrogen attenuates neuron apoptosis by inhibiting ROS and bax expression following traumatic brain injury in rat

目的探讨雌激素在颅脑创伤中发挥保护作用的分子机制。方法按照Marmarou's方法建立大鼠创伤性脑损伤(TBI)模型。100只雄性SD大鼠随机分为创伤组、治疗组和对照组,其中创伤组和治疗组又分为伤后10 min、30min、3 h、6 h、24 h、48 h和72 h 7个时相组。采用硫代巴比妥酸法测定氧自由基中间产物丙二醛(MDA),免疫组化方法检测细胞凋亡相关基因bax的表达,原位缺口末端标记法(TUNEL)检测凋亡细胞。结果雌激素治疗组海马区MDA、bax的表达及TUNEL阳性细胞数均明显低于模型组。结论大鼠脑创伤后,雌激素通过抗氧化作用抑制凋亡基因bax的表达,进而抑制神经细胞凋亡而起到脑保护作用。

Objective To investigate the mechanism of estrogen＇s protection effect on neurons in traumatic brain injury（TBI） in rats.Methods The rat model of TBI was made according to the method of Marmarou＇s（1994）.Male Sprague-Dawley rats were randomly divided into control,TBI and estrogen treatment groups.The rats in TBI and treatment groups respectively were divided into 7 subgroups according to the time phase after brain injury,which were 10 min,30 min,3 h,6 h,24 h,48 h and 72 h.The value of MDA was measured by thio-barbiturie acid.Theexpression of bax was detected by immunohistochemistry and the apoptosis of neurons wasdetected by TUNEL method.Results The value of MDA,immuno-activity of bax and thenumber of TUNEL positive cells of treatment group were lower than TBI group.Conclusion Estrogen attenuates the apoptosis of neurons by reducing oxygen free radical and then bax expression following traumatic brain injury in rats.