王曉東 劉晨 彭瑞云 姚斌偉 周紅梅 楊仕明 于寧
1中國(guó)人民解放軍總醫(yī)院耳鼻咽喉頭頸外科&耳鼻咽喉科研究所(北京100853)
2中國(guó)人民解放軍軍事醫(yī)學(xué)科學(xué)院放射與輻射醫(yī)學(xué)研究所(北京100850)
高功率微波輻射后豚鼠聽(tīng)性腦干反應(yīng)閾值的變化
王曉東1劉晨1彭瑞云2姚斌偉2周紅梅2楊仕明1于寧1
1中國(guó)人民解放軍總醫(yī)院耳鼻咽喉頭頸外科&耳鼻咽喉科研究所(北京100853)
2中國(guó)人民解放軍軍事醫(yī)學(xué)科學(xué)院放射與輻射醫(yī)學(xué)研究所(北京100850)
目的本研究運(yùn)用同一波段、不同功率的微波對(duì)豚鼠照射,觀察豚鼠微波輻射前后聽(tīng)力的變化。方法選取聽(tīng)力正常的SPF級(jí)雄性Hartley豚鼠,隨機(jī)分為對(duì)照組、30mW/cm2組100mW/cm2組,于輻射前、輻射后即刻、3天、7天、14天測(cè)定聽(tīng)性腦干反應(yīng)閾值。結(jié)果100 mW/cm2組輻射后ABR閾值升高,即刻、3天、7天、14天ABR閾移與對(duì)照組差異有顯著統(tǒng)計(jì)學(xué)意義(P<0.05);30mW/cm2組閾移與對(duì)照組差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。結(jié)論本實(shí)驗(yàn)條件下的結(jié)果表明,高功率微波輻射可導(dǎo)致豚鼠ABR閾值升高,但損傷作用與輻射的功率有關(guān)。
聽(tīng)性腦干反應(yīng);微波;豚鼠;氧化應(yīng)激
隨著社會(huì)和科學(xué)的進(jìn)步,微波被廣泛應(yīng)用于軍事、通訊、醫(yī)療等各個(gè)領(lǐng)域,無(wú)線傳輸技術(shù)的普及給人們的生活帶來(lái)巨大便利,身邊的電器、移動(dòng)電話、電腦均需要微波來(lái)傳輸信息,人們無(wú)時(shí)無(wú)刻不處于微波輻射之中,對(duì)健康的潛在危害引起廣泛關(guān)注[1]。研究表明,高功率微波對(duì)人體多個(gè)系統(tǒng)器官具有損傷和不良影響[2-3]。神經(jīng)系統(tǒng)、心血管系統(tǒng)、免疫系統(tǒng)、生殖系統(tǒng)等均是微波損傷的靶器官,可引起神經(jīng)衰弱[4]、記憶力減退、心臟節(jié)律障礙[5-6]、造血功能障礙、精子活力減退等諸多不良后果,并與某些腫瘤的發(fā)生相關(guān)[7-8]。微波對(duì)聽(tīng)力的影響,尚無(wú)明確結(jié)論。S波段的微波頻率在2~4GHz,廣泛應(yīng)用于無(wú)線通訊和軍事領(lǐng)域。本研究運(yùn)用S波段、不同功率而總輻射能量相同的微波對(duì)豚鼠照射,觀察豚鼠微波輻射前后聽(tīng)力的變化。
選取雄性、體重200~250g的Hartley豚鼠15只,均為無(wú)特定病原體動(dòng)物(Specific pathogen Free,SPF),由軍事醫(yī)學(xué)科學(xué)院動(dòng)物實(shí)驗(yàn)中心提供。實(shí)驗(yàn)動(dòng)物飼養(yǎng)于無(wú)特定病原菌、恒溫(20~25℃)恒濕(45%~50%)條件的超凈層流架中。實(shí)驗(yàn)入選條件為:雙耳聽(tīng)性腦干反應(yīng)(Auditory Brainstem Response,ABR)閾值均≤30dB SPL。
照射源為S波段高功率微波輻射源。將動(dòng)物隨機(jī)分為3組,每組5只,實(shí)驗(yàn)組分為30 mW/cm2組和100 mW/cm2組,兩組功率不同,總輻射能相同。30mW/cm2組:用30mW/cm2強(qiáng)度的微波,每天照射15分鐘,連續(xù)3天;
100 mW/cm2組:用100mW/cm2強(qiáng)度的微波,照射1次,15分鐘;
正常對(duì)照組:不予微波照射,其余條件與上述兩組相同。
微波輻射在微波輻射室內(nèi)進(jìn)行,墻壁地面均涂裝微波吸收材料,防止微波在空間中反射,影響動(dòng)物接受輻射的功率。將豚鼠放入特制有機(jī)玻璃動(dòng)物固定盒中,置于圓形輻射臺(tái)上,輻射源在輻射臺(tái)正上方1米處,實(shí)驗(yàn)組標(biāo)示輻射強(qiáng)度為動(dòng)物接收到微波的強(qiáng)度,輻射臺(tái)勻速轉(zhuǎn)動(dòng),使動(dòng)物均勻受照。照射前、照射后即刻(30Mw/cm2組為第三次照射后即刻)、3天、7天、14天對(duì)3組豚鼠進(jìn)行ABR閾值測(cè)試。
ABR閾值測(cè)試采用美國(guó)TDT聽(tīng)覺(jué)誘發(fā)電位工作站(美國(guó)TDT system 3,RZ6),刺激聲為短聲(Click),帶通濾波100~3000Hz,放大增益106,刺激速率20次/秒,相同刺激強(qiáng)度疊加1024次,最大刺激強(qiáng)度為90dB SPL,依次遞減5dB SPL,判斷標(biāo)準(zhǔn)為能重復(fù)出可分辨的ABR波形的最低刺激強(qiáng)度,該強(qiáng)度即判斷為ABR閾值。
文中實(shí)驗(yàn)數(shù)據(jù)以算數(shù)平均數(shù)±標(biāo)準(zhǔn)差代表,運(yùn)用SPSS13.0統(tǒng)計(jì)軟件對(duì)數(shù)據(jù)進(jìn)行統(tǒng)計(jì)學(xué)分析,采用重復(fù)測(cè)量資料方差分析。以P<0.05為差異顯著性標(biāo)準(zhǔn)。
微波照射前,各組動(dòng)物聽(tīng)力均正常(閾值≤30dB SPL),無(wú)顯著性差異。實(shí)驗(yàn)組與對(duì)照組豚鼠在輻射前和輻射后行為無(wú)明顯變化。為直觀反映S波段微波對(duì)豚鼠聽(tīng)力損傷的差異,部分?jǐn)?shù)據(jù)分析時(shí)采用閾移值作為衡量標(biāo)準(zhǔn)(閾移值=測(cè)試時(shí)閾值-照射前閾值)。
正常對(duì)照組:ABR閾值在實(shí)驗(yàn)前后各時(shí)間點(diǎn)差異無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。
30mW/cm2組:輻射后即刻、3天、7天、14天ABR閾移與對(duì)照組的差異均無(wú)統(tǒng)計(jì)學(xué)意義(P>0.05)。
100 mW/cm2組:與對(duì)照組和30 mW/cm2組比較,輻射后即刻(P<0.05)、3天(P<0.05)、7天(P<0.05)、14天ABR(P<0.05)閾移的差異有統(tǒng)計(jì)學(xué)意義。
圖1 豚鼠照射后ABR閾值變化(n=5)Fig.1 HPM radiation lead to increase ofABR threshold(n=5)
表1 高功率微波照射后各組動(dòng)物ABR閾移(dB)(n=5)Table 1 HPM radiation lead to increase ofABR threshold(dB)(n=5)
高功率微波對(duì)生物體的損傷受到廣泛關(guān)注,神經(jīng)系統(tǒng)、心血管系統(tǒng)、免疫系統(tǒng)、生殖系統(tǒng)等均是微波損傷的靶器官。高功率微波對(duì)聽(tīng)覺(jué)系統(tǒng)的損傷效應(yīng)尚無(wú)明確結(jié)論,有部分學(xué)者報(bào)道了微波損傷聽(tīng)覺(jué)系統(tǒng)的研究結(jié)果。于寧等發(fā)現(xiàn)高功率的電磁脈沖可以導(dǎo)致昆明小鼠聽(tīng)覺(jué)腦干反應(yīng)閾值升高[9],馮曉華等發(fā)現(xiàn)長(zhǎng)時(shí)間的微波暴露導(dǎo)致外毛細(xì)胞功能障礙[10]。本研究發(fā)現(xiàn),高功率微波可導(dǎo)致豚鼠ABR閾值升高,并且在相同輻射能量下,功率高者損傷明顯,而低功率組并未引起明顯的閾值變化。研究結(jié)果顯示短時(shí)間內(nèi)接受高功率微波輻射,對(duì)聽(tīng)力的損傷重于長(zhǎng)時(shí)間低功率微波輻射,急性微波損傷對(duì)聽(tīng)力的傷害比慢性微波輻射的影響更大。國(guó)外學(xué)者也有研究表明低功率的微波輻射對(duì)聽(tīng)力的損害無(wú)統(tǒng)計(jì)學(xué)意義[11]。
微波損傷的效應(yīng)機(jī)制尚不明確,目前有多種理論解釋。氧化應(yīng)激反應(yīng)是其重要機(jī)制,這也是微波多系統(tǒng)損傷的共同機(jī)制[12-16]。聽(tīng)覺(jué)細(xì)胞對(duì)氧化應(yīng)激較為敏感,氧化應(yīng)激反應(yīng)是導(dǎo)致耳聾的重要機(jī)制之一[17-18]。微波可引起機(jī)體產(chǎn)生更多的活性氧,正常狀態(tài)下活性氧的產(chǎn)生和消除處于動(dòng)態(tài)平衡,一旦活性氧大量產(chǎn)生,超過(guò)正常代償水平,活性氧可攻擊生物大分子,影響細(xì)胞功能,導(dǎo)致多種疾病的發(fā)生。微波的氧化應(yīng)激理論恰好解釋了本研究中急性微波損傷較重的現(xiàn)象,低功率的微波輻射雖然也可引起機(jī)體活性氧的增加,但通過(guò)機(jī)體代償仍處于動(dòng)態(tài)平衡,不會(huì)短時(shí)間產(chǎn)生大量活性氧導(dǎo)致聽(tīng)覺(jué)細(xì)胞功能異常;隨著微波輻射功率增高,活性氧動(dòng)態(tài)平衡被打破,產(chǎn)生大量活性氧攻擊生物大分子,導(dǎo)致細(xì)胞功能受損,進(jìn)而引起聽(tīng)力的損傷。
本研究結(jié)果表明高功率微波導(dǎo)致豚鼠ABR閾值升高,推斷微波對(duì)人聽(tīng)力可能也存在損傷效應(yīng)。我們將進(jìn)一步研究高功率微波聽(tīng)力損傷的機(jī)制和預(yù)防,同時(shí)建議對(duì)有高功率微波暴露的人員提供必要的防護(hù)措施,同時(shí)呼吁社會(huì)各界加強(qiáng)對(duì)微波聽(tīng)力損傷和防護(hù)的關(guān)注和研究。
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Changes ofAuditory Brainstem Response Thresholds in Guinea Pigs Following High-Power-Microwave Radiation
WANG Xiaodong1,LIU Chen1,PENG Ruiyuan2,YAO Binwei2,ZHOU Hongmei2,YANG Shiming1,YU Ning1
1 Department of Otolaryngology,Head&Neck Surgery,Chinese PLA General Hospital,Beijing 100853,China
2 Institute of Radiation Medicine,PLA Academy of Military Medical Sciences,Beijing 100850,China
Corresponding author:YU NingEmail:yuning12@sina.com
ObjectiveTo report changes in auditory brainstem response threshold in guinea pigs after high-power-microwave radiation.MethodsFifteen male guinea pigs were divided into a control group,a 30 mW/cm2treatment group and a 100 mW/cm2treatment group.Following high-power-microwave,guinea pigs were tested for ABR thresholds immediately and on Days 3,7 and 14.ResultsABR thresholds were elevated in the 100 mW/cm2treatment group at all time points(P<0.05).There was no statistically significant difference between the 30 mW/cm2treatment group and control group at all time points(P>0.05).ConclusionsThe results show that high-power-microwave radiation can lead to a power dose dependent increase ofABR thresholds in guinea pigs.
Auditory Brainstem Response;Microwave;Guinea pigs;Oxidative stress
This work was supported by grants from the National Natural Science Foundation of China(NSFC81470700 and 81528005),the National Basic Research Program of China(973 Program)(#2014CB943002)and PLA Medical Technology key project of scientific research(JDZYY20132).
R764
A
1672-2922(2017)05-552-3
10.3969/j.issn.1672-2922.2017.010.
及編號(hào):自然基金項(xiàng)目(81470700、81528005)、國(guó)家973項(xiàng)目(2014CB943002)及全軍衛(wèi)勤重點(diǎn)項(xiàng)目(JDZYY20132)
王曉東,本科,主治醫(yī)師,研究方向:耳聾機(jī)制研究
于寧,Email:yuning12@sina.com
2016-05-06審核人:馮艷梅)