【摘要】 目的探讨铅对中枢神经系统神经细胞内转录因子Brn-3a表达的影响及诱导细胞凋亡的作用。方法20只受孕SD大鼠随机分为4组,经围产期饮水染铅(0、0.5、1.0、2.0g/L)后,对其21日龄仔鼠不同脑区的Brn-3a蛋白表达水平进行观察,采用流式细胞仪测定细胞凋亡率及应用间接免疫荧光反应测定Bcl-2蛋白的表达情况。结果染铅组大鼠大脑皮层、海马及小脑的Brn-3a蛋白表达的阳性面积比、平均灰度与对照组比较,其差异均有统计学意义(P<0.05或P<0.01),并呈剂量依赖性的变化,Brn-3a表达低于对照组;染铅组大鼠海马组织细胞凋亡率高于对照组(P<0.01);染铅组大脑皮层、海马、小脑部位Bcl-2蛋白表达下降(P<0.05或P<0.01)。结论铅对发育期神经组织的损害可能与其诱导的神经细胞凋亡相关联,铅致Brn-3a蛋白表达下降可能是铅致神经细胞凋亡的途径之一。更多还原

【Abstract】 Objective To explore the effects of lead on the expression of Brn-3a transcription factor and apoptosis in the neurons of central nerve system Methods The SD pregnant rats were randomly divided into 4 groups fed with distilled water and lead contained water (0.5, 1.0, and 2.0 g/L lead actate) respectively,the lead-exposure period was from the 15th day of pregnancy to the offspring weaned. Expression of Brn-3a, Bcl-2 proteins, the rate of apoptosis of neural cells were measured. Results The immunohistochemistry results showed that the Brn-3a decreased significantly in lead exposed groups compared with the control (P<0.05 or P<0.01); the rate of apoptosis in neurons of hippocampus in high lead exposed group was significantly higher than that of control(P<0.01); the expression of Bcl-2 was significantly decreased in neurons of cerebral cortex, hippocampus and cerebellum in every lead treated group compared with the control(P<0.05 or P<0.01). Conclusion The apoptosis is partly related to the impairment of central nerve system caused by lead and down regulation of expression of Brn-3a may be one important factor in the mechanism of the apoptosis induced by lead in brain.更多还原