【摘要】 目的观察新生大鼠缺氧缺血性脑损伤(HIBD)后,外源性转化生长因子β1(TGF-β1)对脑组织Bcl-2及Bax蛋白表达的影响。方法48只7日龄新生大鼠随机分为假手术组、HIBD组、生理盐水对照组,TGF-β1干预组,其中TGF-β1干预组又分大、中、小剂量三组。建立HIBD模型2 h后,侧脑室注入不同剂量(20 ng、10 ng5、ng)的TGF-β1,免疫组织化学方法观察给药24 h后脑组织Bcl-2及Bax蛋白表达的变化。结果HIBD组及生理盐水对照组较假手术组Bcl-2及Bax蛋白表达均显著增高,Bcl-2/Bax比值显著降低,TGF-β1干预组较HIBD组及生理盐水对照组Bcl-2蛋白表达及Bcl-2/Bax比值显著增高,Bax蛋白表达显著降低。结论TGF-β1可以通过上调Bcl-2蛋白表达及下调Bax蛋白表达,改变Bcl-2与Bax蛋白表达比例,抑制细胞凋亡,从而起神经保护作用,为TGF-β1临床治疗HIBD提供了理论依据。更多还原

【Abstract】 Objective To explore the effect of exogenous TGF-β₁ on the expression of Bcl-2 and Bax protein in brain tissue following hypoxic-ischemic brain damage（HIBD） in newborn rat.Methods Unsexed 7-day-old Wistar rats were randomly divided into sham operation group,HIBD group,saline-treated control group and TGF-β₁-treated group.The TGF-β₁-treated group was divided into groups of high,middle and low dose.After the HIBD model was performed,different TGF-β₁ dosages（20?ng、10?ng、5?ng） were injected into the left lateral ventricle.The expression of Bcl-2 and Bax protein at 24?h after injection were measured by immunohistochemical method.Results the expression of Bcl-2 and Bax protein in HIBD group and saline-treated control group were significantly higher in comparison with that in sham operation group,the Bcl-2/Bax ratio was significantly lower.the expression of Bcl-2 protein and the Bcl-2/Bax ratio in TGF-β₁-treated group were significantly higher than HIBD group and saline-treated control group,the expression of Bax protein was significantly lower.Conclusion The neuronal protective mechanism of TGF-β₁ might be related to up-regulating the expression of Bcl-2 protein,down-regulating the expression of Bax protein and alter the Bcl-2/Bax ratio in brain tissue,consequently it could inhibit the apoptosis of neuron after HIBD.更多还原