大鼠脑皮层冲击伤中BCL-2、BAX的表达变化

BCL-2 and BAX expression in cortex of blast injuried rats

目的探讨爆炸冲击伤中大鼠脑皮层BCL-2、BAX基因表达的变化规律。方法应用爆炸冲击波致伤大鼠，致伤后不同时间（12～96h），光镜和电镜观察脑皮层形态变化；免疫组织化学方法观察BCL-2和BAX蛋白在脑皮层表达；凝胶电泳法观察大鼠脑组织DNA电泳结果。结果爆炸后12～96h，光镜和电镜观察脑皮层细胞凋亡改变增多；爆炸后24h脑组织BCL-2、BAX基因表达阳性细胞率均最高（P〈0．01），BCL-2／BAX表达比值随时间延长而降低（P〈0．01）；脑组织DNA电泳在爆炸后12、24和48h组形成典型阶梯状条带；上述改变以24h组最明显。结论爆炸冲击伤可导致部分脑皮层神经元的细胞凋亡，BCL-2和BAX表达比值下降。

Objective To observe potential changes in the BCL-2 and BAX gene expression in rat brain mantle during the explosive blast injury. Methods Explosion shock was used to induce blast injury in rat. From 12 h to 96 h after the blast injury, light microscopy and electron microscopy were used to observe the morphologic changes in rat brain mantle. Immunochemical method was used to study the expression of BCL-2 and BAX proteins in rat brain mantle, and gel electrophoresis was used to observe the changes in DNA ladder. Results During the postburst phase （12- 96 h）, the increased apoptosis in brain mantle was observed by light microscopy and electron microscopy. The rate of BCL-2 and BAX positive ceils was the highest 24 h after injury, with time their rate descending gradually in brain after the explosion （P 〈 0. 01 ）. DNA electrophoresis showed a typical ladder shape in 12 h group, 24 h group and 48 h group. Above-mentioned changes were the most significant in 24 h group. Conclusion The explosive blast injury may cause apoptosis of some cerebral cortical neurons and the decline of BCL-2/BAX rate.