电磁辐射对大鼠海马超微结构及凋亡因子影响

Effect and its mechanisms of electromagnetic radiation on ultrastructure and apoptosis-related genes in rats' hippocampus

目的探讨2 000μW/cm2电磁辐射对大鼠海马神经元超微结构及凋亡相关因子表达影响。方法实验分空白对照组,假辐射组,1、2、3 h/d辐射组,采用2 000μW/cm2微波对大鼠头部进行辐射,透射电镜观察海马超微结构改变,免疫组织化学法检测海马组织Bcl-2、Bax表达,蛋白免疫印迹(western-blot)法检测海马组织Caspase-3表达。结果辐射组神经元细胞核仁消失,染色质凝集,核内出现透明区等早期凋亡征象,突触界面结构改变;1、2、3 h/d辐射组Bax表达分别为(0.059 8±0.005 1)、(0.066 3±0.006 1)、(0.086 9±0.007 3),Caspase-3表达分别为(0.56±0.04)、(0.74±0.05)、(0.94±0.03),高于对照组(P<0.05);1、2、3 h/d辐射组Bcl-2表达分别为(0.056 9±0.0087)、(0.052 4±0.007 8)、(0.042 3±0.001 4),低于对照组(P<0.05)。结论电磁辐射可引起海马神经元细胞损伤和凋亡,其机制与凋亡相关因子Bc1-2、Bax、Caspase-3表达改变有关。

Objective To evaluate the effects of 2000 μW/cm2 electromagnetic radiation on hippocampus ultrastructure and apoptosis-related genes. Methods Totally 100 Wistar rats were randomly divided into normal control,sham-radiated,and 1,2 and 3 hours/per day radiation groups.The rats in the radiation groups were exposed to microwave of 2000 μW/cm2 on their heads and then the morphological changes in the hippocampal neurons were detected by transmission electronic microscopy and the expressions of Bcl-2 and Bax protein were detected by immnunohistochemistry and the expression of caspase-3 by western-blot. Results Microscopic observation revealed that the chromatin coacervation and chromatin of hippocampal neurons gathered along the inside of the nuclear membrane in radiation group.The structure of synaptic interface changed.Compared with the normal control group,the expression of Bax and caspase-3 protein increased and Bcl-2 protein decreased in radiation group. Conclusion The electromagnetic radiation exposure of 2 000 μW/cm2 can induce the abnormality of neuronal apoptosis in rat hippocampus.The machanism of hippocampus neuron injury involves in the expression of apoptosis related genes,such as Bc1-2,Bax,and caspase-3.