手机电磁辐射对耳蜗超微结构及边缘细胞的影响

Effects of mobile phone electromagnetic radiation on ultrastructure and marginal cells of cochlea

目的探讨900MHz手机电磁辐射对大鼠耳蜗超微结构及边缘细胞的影响。方法选择成年SD大鼠40只,通过每日接受不同时长900MHz手机电磁辐射暴露28d建立手机电磁辐射大鼠模型,分为对照组、辐射6 h组、辐射12 h组和辐射24 h组。电磁辐射暴露后,测试大鼠的听性脑干反应(ABR)、40 Hz听觉事件相关电位和听觉稳态反应的反应阈以评价电磁辐射对大鼠听觉功能的影响;扫描电镜及苏木精-伊红染色后光镜下观察耳蜗超微结构;彗星实验检测耳蜗边缘细胞DNA损伤情况;流式细胞仪检测电磁辐射对边缘细胞凋亡的影响及活性氧水平。结果手机电磁辐射后大鼠听觉功能各指标反应阈值均高于对照组(P值均<0.05);大鼠耳蜗超微结构随每日暴露时长增加而出现不同程度的外毛细胞纤毛排列及结构异常、柯蒂器形态改变和耳蜗内红细胞渗出等;大鼠耳蜗边缘细胞的DNA损伤情况及细胞凋亡率在各组间差异无统计学意义(P>0.05);辐射24 h组的活性氧水平显著高于对照组(P<0.001),其余组与对照组间差异无统计学意义(P值均>0.05)。结论长时间手机电磁辐射可引起大鼠耳蜗超微结构损伤,并导致听觉功能下降,但不足以引起耳蜗边缘细胞的DNA损伤和凋亡,更长时间的辐射暴露会引起活性氧水平升高。

Objective To investigate the effect of 900 MHz mobile phone electromagnetic radiation on ultrastructure and marginal cells of cochlea in rats.Methods Forty adult SD rats were selected and exposed to 900 MHz mobile phone electromagnetic radiation for different time per day for a total of 28 days in order to establish the mobile phone electromagnetic radiation rat models.The rats were divided into the control group,radiation for 6 h group,radiation for 12 h group and radiation for 24 h group.After exposure to electromagnetic radiation,the auditory brainstem response,40 Hz auditory event-related potential and auditory steady-state response threshold of rats were tested to evaluate the effect of electromagnetic radiation on auditory function of rats.The ultrastructure of cochlea was observed under scanning electron microscope and light microscope after hematoxylin-eosin staining.DNA damage in cochlear marginal cells was detected by comet assay.Flow cytometry was used to measure the effect of electromagnetic radiation on apoptosis of marginal cells and the level of reactive oxygen species.Results The response thresholds of each index of auditory function in rats after mobile phone electromagnetic radiation were all higher than those in the control group(P<0.05).With the increase of daily exposure time,the ultrastructure of rat cochlea showed varying degrees of abnormal arrangement and structure of outer hair cell cilia,morphological changes of organ of Corti and diapedesis of erythrocyte in cochlea.There was no significant difference in DNA damage or apoptosis rate of rat cochlear marginal cells among groups(P>0.05).The reactive oxygen species level in the radiation for 24 h group was higher than that in the control group(P<0.001),while there was no significant difference among the other groups and the control group(P>0.05).Conclusions Long-term mobile phone electromagnetic radiation can cause the ultrastructure damage of rat cochlea and decrease the auditory function,but it is not enough to cause the DNA damage and apoptosis of cochlear marginal cells.Longer radiation exposure can cause the increase of reactive oxygen species.