新生大鼠脑缺血时海马区bc1-2基因的表达

目的通过研究新生大鼠脑缺血时bcl-2基因在海马区的表达特点,探讨bcl-2基因在神经元凋亡中的作用。方法54只7日龄新生SD大鼠随机分为1个对照组和8个实验组。给动物吸入含有92%氮气和8%氧气的混合气体建立新生大鼠缺血缺氧脑损伤动物模型,分别在脑损伤后不同时间点(0.5、1、3、6、12、24、48、72 h等)断头处死动物,取海马组织,用免疫组织化学方法检测海马脑神经细胞凋亡及bcl-2基因表达情况。结果各组海马脑区阳性凋亡细胞的病理变化是染色质固缩边集、细胞质浓缩,胞浆内出现浓染颗粒,核膜也可出现,质膜分隔胞质,可形成凋亡小体。TUNEL染色的阳性细胞数与bcl-2蛋白阳性的细胞数在HIBD后的不同时间点出现分别有显著差异(FTUNEL=334.0,PTUNEL<0.01;Fbcl-2=42.7,Pbcl-2<0.01)。凋亡阳性细胞出现与bcl-2蛋白表达在12 h呈负相关(γ=-0.79,P<0.05)。HIBD后0.5~12 h,bcl-2蛋白表达越多,阳性凋亡细胞越少。海马区bc1-2蛋白阳性细胞在HIBD后立即出现,6 h达到高峰,之后渐下降。结论bc1-2基因强表达于海马缺血区和缺血周边区的神经元,与神经元的存活或死亡有一定联系。

The expression of bcl-2 gene in hippocampus area of neonatal rats with hypoxic ischemic brain damage

Objective To explore the effect of bcl-2gene in cell apoptosis of neuron by studying the expression of bc1-2 gene in hippocampus area of neonatal rat with hypoxic ischemic brain damage(HIBD).Methods Fifty-four neonatal rats were stochastically divided into 1 control group and 8 trial groups.The HIBD in neonatal rat were established by inhaling the mixed gases of 92%N_2 and 8%O_2,then the animals were sacrificed by dislocating their heads at different time points(0.5,1.0,3.0,6.0,12.0,24.0,48.0,72.0h),and the hippocampus tissue were taken out.The brain nerve cell apoptosis and the expression of bc1-2 gene were detected.Results The pathology change of the positive apoptosis cells in every group's rats are that the chromatin shrank and collected,the cytoplasm condensed and there are densely dyed grain.The apoptotic cells appeared at the time point of 3h,and reached the peak at 48 h,then decreased.the positive cell of bcl-2 protein increased from the time point of 30 min and reached the peak at 6h and then decreased gradually following HIBD.Conclusion The expression of bc1-2 gene in hippocampus was stronger than other areas of brain,and there is some relativity between cell apoptosis and exprssion of bc12 gene.