Bcl-x,BaxmRNA在新生大鼠脑缺氧缺血后的表达及其与脑细胞凋亡的关系

THE RELATIONSHIP BETWEEN THE EXPRESSION OF BCL X, BAX mRNA AND BRAIN CELLS APOPTOSIS FOLLOWING CEREBRAL HYPOXIA ISCHEMIA.

探讨新生动物缺氧缺血性脑损伤后细胞死亡相关基因bcl x ,bax表达的变化规律及其与神经细胞凋亡的关系。建立新生大鼠缺氧缺血性脑病动物模型 ,应用快速竞争性RT PCR及原位末端标记法观察脑缺氧缺血后不同时间点缺氧缺血侧大脑组织中bcl x ,baxmRNA的表达及神经细胞凋亡的情况。结果显示缺氧缺血后新生大鼠脑bcl xsmRNA的表达自缺氧结束后即刻即有明显增强 ,2 4h达高峰 ,此后逐渐下降 ,7d时回复至正常基线水平。而baxmRNA的表达自缺氧缺血后 2h开始明显增加 ,2 4h达高峰 ,7d时回复至正常基线水平。缺氧缺血侧脑组织中凋亡细胞数亦自缺氧缺血后 6h明显增多 ,并于 2 4h达高峰。bcl xs ,baxmRNA的表达高峰与缺氧缺血后脑细胞凋亡的高峰时相相吻合。缺氧缺血对bcl xlmRNA的表达无影响。研究表明缺氧缺血可使新生大鼠脑bcl xs ,baxmRNA的表达增强和凋亡细胞增加 ,但对bcl xlmRNA的表达无影响。bcl xl

To invertigate the relationship between bcl x, bax mRNA and brain cells apoptosis following cerebral hypoxia ischemia in the neonatal rats. Using 7 day oly rat pups were subjected to a unilateral ligation of the common carotid artery following by a 2h 30min hypoxic period (8%O 2 inN 2). Rapid competitive reverse transcriptase PCR and in situ end labeling methods were used to detect the expression of bcl x, bax mRNA and brain cells apoptosis separately in the hemisphere subjected to both ligation and hypoxia at different time points after hypoxiaischemia. Results Shoured the expression of bcl xs mRNA in the ipsilateral hemisphere following cerebral hypoxia ischemia increased markedly at the termination of hypoxic exposure, peaked at 24h, and returned towards baseline at 7d, while the overexpression of bax mRNA began at 2h after recovery, peaked at 24h, and retuned to wards baseline at 7d, while the overexpression of bax mRNA began at 2h after recovery, peaked at 24h, and retuned towards baseline at 7d(n=5/time point). The increase of apoptotic cells in the ipsilateral hemisphere also began at 6h after recovery, and peaked at 24h. The jpeak time of the overexpression of bcl ex and bax was coordinate with that of apoptosis following hypoxia ischemia. Hypoxia ischemial had no effect on the expression of bcl xl mRNA. The increase in expression of bax, bcl xs mRNA and then the cell apoptosis could be induced by cerebral hypoxia ischemia, but hypoxia ischemia had no effect on the the expression of bcl xl mRNA. The ratio of bcl xl to bax could play an important role in the induction of apoptosis following cerebral hypoxia ischemia.OC curve method combines Se and Sp to estimate the diagnostic critical value of disease index and determine the veracity by the area under the curve,this method has the practical value for clinical diagnosis when ROC curve area is 0 70 9 and NCr was 84 9.