摘要
目的观察强脉冲噪声暴露后早期大鼠耳蜗毛细胞损伤发展的规律。方法将大鼠暴露于平均压力峰值级为154dBSPL的脉冲噪声100发,分别于噪声暴露后10min、30min、3h、6h解剖取耳蜗,应用碘化丙锭(PI)标记耳蜗基底膜,荧光显微镜下观察脉冲噪声暴露后耳蜗毛细胞凋亡和坏死的时程特点。结果强脉冲噪声暴露后10min出现外毛细胞核染色质移位及凋亡小体,30min可见到少量肿胀的外毛细胞核,3h观察到少量外毛细胞核的缺失。6h耳蜗基底膜损伤区出现大片外毛细胞核缺失和部分微小球形固缩的外毛细胞核。结论耳蜗外毛细胞死亡发生于强脉冲噪声暴露后即刻,外毛细胞凋亡先于坏死。细胞凋亡过程迅速,强脉冲噪声暴露后6h耳蜗基底膜损伤区大部分死亡细胞已被清除。
Objective To observe the space-time patterns of damaged outer hair cells（OHCs） in rat cochlea at the early stage after exposure to impulse noise. Methods Wistar rats were exposed to 100 emissions of impulse noise （3 seconds interval between each emission） at 154 dB SPL. Four times （10 min, 30 min, 3h and 6h） after tile noise exposure, the animals were sacrificed and the organs of Corti were processed for detection of OHC death modes. The apoptotic and necrotic OHCs were distinguished by propidium iodide （PI）, a fluorescent probe specifically labeling the nuclear DNA. The specimens were examined under a fluorescence microscope for assessment of OHC damage. Results Nuclear chromatin began to shrink as the chromatin condensed around the nuclear periphery. The peripheral chromatin ring condensed into discrete mass. Chromatin masses appeared to bleb off from the nuclear surface, forming apoptotic bodies at 10 rain after the noise exposure. There were a few swollen nuclei appeared 30 min after the noise exposure. Loss of OHC nuclei could be seen 3 h after the noise exposure. The cochlear lesion expanded to contain a large number of missing OHCs and seriously shrunken nuclei at 6 h after the noise exposure. Conclusions The results of the study indicate that death of OHCs takes place extremely rapid after the impulse noise exposure. The apoptosis of OHCs precedes necrosis. OHC apoptosis is a quick process. Most of dead outer hair cells were elimioated 6 h after the noise exposure.
出处
《解放军医学杂志》
CAS
CSCD
北大核心
2006年第6期543-544,共2页
Medical Journal of Chinese People's Liberation Army
基金
全军"十五"医药卫生科研基金课题资助项目(01L047
关键词
耳蜗
毛细胞
外
噪声
凋亡
坏死
大鼠
cochlea
hair cells, outer
noise
apoptosis
necrosis
rat
作者简介
杨卫平，医学硕士，研究员。主要从事聋病的发生机制及防治研究。已发表论文30余篇，E-mail：yangwp@301hospital．com．cn
