雌激素对豚鼠风洞噪声性听功能损伤及内耳Caspase-3表达的影响  

Effects of estrogen on hearing organ damage caused by wind tunnel noise exposure in guinea pigs

作　　者：吴玮[1] 韩浩伦[1] 王方园[1] 王鸿南[1] 李保卫[1] 王刚[1] 屈昌北[1] 孟令照[1] 薄少军[1] 丁瑞英[1] 刘刚[2] 孙建芝[1] 刘红丹[1] 王媛媛[1] 

机构地区：[1]解放军第306医院耳鼻咽喉头颈外科,北京100101 [2]中国航天员科研训练中心,北京100193

出　　处：《中华耳科学杂志》2012年第3期387-391,共5页Chinese Journal of Otology

基　　金：全军医药卫生科研基金项目(06MA008)

摘　　要：目的探讨风洞噪声环境对豚鼠听功能及内耳毛细胞、螺旋神经节细胞上凋亡标志物Caspase-3表达的影响,并通过噪声暴露前给予预防用腹腔注射雌激素研究雌激素对噪声暴露后豚鼠听力损伤及内耳凋亡的保护作用。方法 42只豚鼠随机分为3组,其中对照组6只,单纯噪声组(噪声组)及噪声+雌激素预防组(雌激素组)各18只。两实验组暴露于模拟风洞噪声环境中。分别于噪声暴露前(Pr)、暴露后1天(E1)、3天(E3)、7天(E7)、恢复后3天(R3)、7天(R7)检测其双侧听性脑干反应阈值(ABR)。并于E3、E7、R7时间点取实验动物耳蜗行连续冰冻切片,利用免疫组织化学染色方法显示凋亡标志物Caspase-3在实验动物内耳毛细胞及螺旋神经节细胞上的表达。结果 E1、E3、E7时间点,噪声组ABR阈值较噪声暴露前明显增高(P<0.01),且暴露时间越长,ABR阈值增高越明显。雌激素组在E1的ABR阈值较噪声暴露前明显增高(P<0.01),E3和E7时ABR阈值有增高趋势,但统计学分析无显著性差异(P>0.05)。两实验组间噪声暴露后听阈变化值在E1和E3点没有统计学差异(P>0.05),在E7点统计学有显著差异(P<0.01)。R3点较E7点,噪声组ABR阈值降低(P<0.05)。雌激素组在R3时间点,ABR阈值明显降低(P<0.01),与R7点比较未见显著性差异(P>0.05);两实验组间比较雌激素组的实验动物ABR阈值降低情况明显优于噪声组(P<0.01)。噪声暴露后,豚鼠内耳螺旋神经节细胞及毛细胞的凋亡标志物Caspase-3表达在各时间段均高于对照组,且随着暴露时间的延长逐渐增高。雌激素组Caspase-3表达变化有相同趋势,但在E3、E7及R7三时间点均弱于噪声组。结论豚鼠暴露于风洞噪声环境下可导致其听功能损伤,损伤程度在本研究噪声暴露时间内与噪声累积量呈正相关。噪声暴露结束后,听力损失可部分恢复。同时,内耳凋亡标志物的表达和听力下降呈现相同趋势。噪声暴露前预�Objectives To study effects of wind tunnel noise on hearing function and on expression of Caspase-3 （apoptosis marker）in inner ear hair cells and spiral ganglion cells, and potential protective effects of intraperitoneal estrogen given before noise exposure against hearing loss and apoptosis. Methods Guinea pigs （n=42） were randomly divided into a control group （n=6）, a noise only group （noise group, n=lS） and estrogen treatment group （estrogen group, n=lS）. Noise group and estrogen group were exposed to a simulated wind tunnel noise environment. Auditory brainstem response （ABR） thresholds were tested bilaterally and cochlear frozen sections were prepared to examine expression of Caspase-3, an apoptotic marker, in inner ear hair cells and spiral ganglion cells by immunohistochemical staining. Time points included pre-noise exposure （pr）, day 1 of exposure （E3）, day 3 of exposure （E3）, day 7 of exposure （ET）, 3 days after exposure （R3） and 7 days after exposure,（RT）. Results ABR thresholds at El, E3, E7 were significantly higher than before exposure （P 〈0.01）in the noise group, and the longer the exposure, the higher the thresholds. ABR thresholds at E1 in the estrogen group were also higher than before exposure （P 〈0.01）. While thresholds in this groups continued to increase at E3 and E7, the increase was not statistically significant （P 〉 0.05）. ABR thresholds at E1 and E3 were not statistically different between the noise group and the estrogen group （P 〉 0.05）, although the difference between the two groups was statistically different at E7 （P 〈0.01）. ABR thresholds of the noise group gradually recovered at R3 and R7 （P 〈0.05）. In the estrogen group, ABR thresholds recovered significantly at E3 （P 〈0.01） which were not significantly different at R7 （P 〉 0.05）. Between the two groups, the recovery of ABR threshold in the estrogen group was significantly better than that in the noise group （P 〈0.01）. Caspase-3

关 键 词：风洞噪声 听性脑干反应 细胞凋亡 CASPASE-3 雌激素 

分 类 号：R764.3[医药卫生—耳鼻咽喉科]