手机微波辐射对豚鼠耳蜗外毛细胞膜电位的影响

Effects of Mobile Phone on Outer Hair Cells Membrane Potential in Guinea Pig Cochlear

目的探讨手机微波辐射对豚鼠耳蜗外毛细胞膜电位的影响。方法取成年豚鼠20只随机分为对照组和辐射组,每组各10只。对照组不做任何处理;辐射组:距豚鼠右侧耳廓2cm处对辐射组豚鼠进行手机微波辐射,辐射时间分别为1、6、12、24和48h,然后分别于各时间点随机活杀两组中的豚鼠各2只,取出听泡,分离耳蜗外毛细胞,用2 000Hz纯音进行不同强度的声刺激,观察离体单个外毛细胞(OHC)膜电位的变化特征。结果对照组离体单个OHC予2 000Hz、10dB HL纯音刺激时,于第40s细胞内荧光值开始升高,并于第50s达到峰值(1.112u),随后细胞内荧光值开始回落,于第60s至最低值(1.000u)。辐射组微波辐射1小时后,OHC细胞膜的去极化和复极化时间明显增加,并且不能完全去极化和复极化;辐射6和12h后,随着间断的声刺激可见OHC内荧光值缓慢上升,辐射6小时组之毛细胞于第70s荧光值达峰值(1.100u),而辐射12小时组之毛细胞于第90s荧光值达峰值(1.050u),随后整条曲线呈微上升趋势;辐射24和48h后,经过声刺激,曲线呈微上升、微下降波动,无明显峰值及回落。结论长时间的手机微波辐射能导致离体豚鼠耳蜗OHC膜离子通透性的改变,影响OHC膜电位的形成及细胞去极化、复极化,从而导致离体OHC膜电位对不同强度纯音刺激的敏感性逐渐降低。

Objective To investigate the effects of mobile phone on outer hair cells membrane potential in guinea pig cochlear. Methods Twenty guineapigs were randomly divided into two groups： control group and exposed group,with 10 animals in each group.Within 2 cm from the right ear of guinea pigs for microwave radiation from mobile phone,guinea pigs were exposed to continuous time of 1 hour,6 hours,12 hours,24 hours and 48 hours.At different time point,2 guinea pigs were randomly sacrified in each group.After isolating outer hair cells from guinea pig cochlear,by 2 000 Hz pure tone acoustic stimulation of different intensity membrane potential of isolated outer hair cells were observed. Results Control group of the first 40 s 2 000 Hz of 10 dB HL pure tone acoustic stimuli was given to OHC,fluorescence value in the cells began to increase,and 50 s at the first peak（1.112 u）,then began to fall,to the lowest value at the first 60 s（1 000 u）.Exposed group after 1 hour radiation,OHC membrane depolarization and repolarization time increased significantly,and would not be completely depolarization and repolarization.After exposure of 6 hours and 12 hours,with the intermittent sound stimulation would be seen slowly rising fluorescence within the OHC.Radiation six hours of hair cells in the first group of 70s peak value of fluorescence（1.100u）,while radiation 12 hours group of 90s hair cells in the first peak value of fluorescence（1.050u）. Then the whole curve slightly upward trend.24 and 48 hours after radiation,after the sound stimulation,the curve was slightly increased and slightly decreased,no significant peak and decline. Conclusion Outer Hair cells in the control group,the depolarization time of the first 10s and was completed within repolarization.However,1 hour after radiation,the outer hair cell depolarization at time of the first 15s,70s started the first repolarization,and can not be completely re-polarization and depolarization.Six hours continuous microwave radiation,the outer hair cells have no significant depolarization and repolarization process.Twenty-four and 48 hours after radiation,membrane potential was only slight,irregular fluctuations,no significant depolarization process.