模拟载人飞船内微重力和噪声环境下大鼠耳蜗毛细胞的形态学变化

发布时间：2018-03-06 14:00

  本文选题：失重模拟　切入点：耳蜗　出处：《北京大学学报(医学版)》2017年03期 　论文类型：期刊论文

【摘要】：目的:观察模拟载人飞船中微重力和噪声环境下大鼠耳蜗毛细胞的形态学特点,探讨耳蜗三回(底回、中回和顶回)毛细胞的不同变化。方法:选取32只雄性健康SD大鼠,随机分为空白组、失重组、噪声组和失重+噪声组4组,每组8只。失重组以持续尾吊法模拟微重力,噪声组以持续2周的(72±2)d B SPL的稳态噪声及之后的3次高达160 d B SPL的脉冲噪声模拟飞船内复合噪声环境,失重+噪声组同时给予模拟微重力和噪声环境,空白组不做任何处理,常规饲养2周。暴露后检测听性脑干反应(auditory brainstem response,ABR)阈值,处死大鼠即刻取耳蜗基底膜行免疫荧光及扫描电子显微镜(scanning electron microscope,SEM)观察。结果:给予模拟环境暴露后,各组大鼠ABR阈值升高,各实验组大鼠暴露前后ABR阈值差异均有统计学意义(P0.05)。免疫荧光结果显示:失重组底回以内毛细胞缺失为主,中回可见毛细胞肿胀,顶回毛细胞杂乱不清。噪声组底回以外毛细胞缺失为主,多见于最外层毛细胞,中回毛细胞肿胀,顶回杂乱并有毛细胞的缺失。失重+噪声组底回核缺失较明显,主要存在最外层毛细胞,内毛细胞也存在较多缺失。中回和顶回缺失发生在最内层外毛细胞。电子显微镜观察发现失重组底回纤毛大片倒伏,偶有缺失,顶回和中回毛细胞纤毛无明显异常。噪声组底回纤毛大片倒伏伴缺失,顶回和中回均有缺失,其中顶回最为严重。失重+噪声组底回纤毛大片融合伴缺失,中回纤毛融合、倒伏并缺失,顶回内外毛细胞纤毛大量缺失。4组的损伤程度:失重+噪声组噪声组失重组空白组;三回毛细胞损伤程度:底回中回顶回。结论:模拟载人飞船内微重力和噪声环境中暴露2周可致大鼠耳蜗形态学结构发生显著变化,尤以失重+噪声组变化最明显,三回毛细胞中以底回最重,顶回最轻。
[Abstract]:Objective: to observe the morphological characteristics of cochlear hair cells in simulated manned spaceship under microgravity and noise, and to explore the different changes of hair cells in the third gyrus of cochlea (bottom gyrus, middle gyrus and parietal gyrus). Methods: 32 male healthy SD rats were selected. They were randomly divided into four groups: blank group, lost recombination group, noise group and weightlessness noise group, with 8 rats in each group. The noise group was simulated with the steady state noise of 72 卤2kb SPL for 2 weeks and the pulse noise up to 160dB SPL three times thereafter. The weightless noise group was given the simulated microgravity and noise environment at the same time, and the blank group did not do any processing. The auditory brainstem response (ABR) threshold was detected after exposure, and the cochlear basement membrane was immediately taken from the rats for immunofluorescence and scanning electron microscopy (SEM). Results: after exposure to simulated environment, the rats were exposed to simulated environment. The ABR threshold of each group was increased, and the difference of ABR threshold was statistically significant before and after exposure in each experimental group (P 0.05). The results of immunofluorescence showed that the loss of hair cells was mainly within the basal gyrus and the swelling of hair cells was observed in the middle gyrus. The loss of outer hair cells in the noise group was mainly seen in the outermost hair cells, the hair cells in the middle gyrus were swollen, the hair cells in the middle gyrus were swollen, and the hair cells were lost in the hair cells of the parietal gyrus. The loss of the nucleus of the bottom gyrus in the noise group was more obvious than that in the noise group. There are mainly outer layers of hair cells, and there are many deletions in inner hair cells. The deletions of middle gyrus and parietal gyrus occur in the inner outer layer of hair cells. There was no obvious abnormality in the cilia of the parietal gyrus and the middle gyrus. In the noise group, there was a loss of large area of the cilium in the bottom gyrus, and the absence of both the parietal gyrus and the middle gyrus, among which the most serious was in the parietal gyrus. The degree of damage in the group of mass loss of ciliated hair cells inside and outside the parietal gyrus: the noise group of weightlessness noise group lost the regrouping blank group; Conclusion: exposure to simulated microgravity and noise for 2 weeks can cause significant changes in cochlea morphology in rats, especially in weightlessness noise group. Of the three hair cells, the bottom gyrus is the heaviest and the terminal gyrus the lightest.
【作者单位】： 中国人民解放军306医院耳鼻咽喉头颈外科;
【基金】：全军“十二五”重大课题(AWS11J003)资助~~
【分类号】：R85
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本文编号：1575123