【摘要】：1目的 感音神經(jīng)性聾是耳科常見的疾病，高頻區(qū)聽力易損性是其最顯著的特點(diǎn)。有研究顯示，感音神經(jīng)性聾的發(fā)生與耳蝸感覺神經(jīng)細(xì)胞的氧化損傷存在著密切的關(guān)系。而螺旋神經(jīng)節(jié)細(xì)胞作為耳蝸內(nèi)重要的感覺神經(jīng)細(xì)胞雖然在感音神經(jīng)性聾發(fā)生的早期往往沒有明顯的形態(tài)學(xué)損傷，但其同樣受到了氧化應(yīng)激作用的影響，致使氧化應(yīng)激相關(guān)分子的表達(dá)與性質(zhì)發(fā)生了變化。且這種變化在螺旋神經(jīng)節(jié)的不同區(qū)域之間存在著差異。其中抗氧化劑的區(qū)域性分布差異及活性變化體現(xiàn)了不同區(qū)域的細(xì)胞抗氧化能力的差異。本研究中，我們主要驗(yàn)證了在噪聲刺激前后線粒體內(nèi)抗氧化酶錳超氧化物歧化酶（Mn-SOD）在大鼠螺旋神經(jīng)節(jié)不同區(qū)域表達(dá)和活性的差異與高頻聽力易損性在區(qū)域上的相關(guān)性。 2方法 本實(shí)驗(yàn)通過給予白噪聲115dB2h連續(xù)3d，建立SD大鼠噪聲性聾的動(dòng)物模型，ABR測(cè)聽分析不同頻率的噪聲損傷情況;免疫組織化學(xué)染色法和western-blot分析噪聲暴露前后Mn-SOD在螺旋神經(jīng)節(jié)不同區(qū)域的表達(dá)水平;黃嘌呤氧化酶法檢測(cè)Mn-SOD在螺旋神經(jīng)節(jié)不同區(qū)域的活性及變化趨勢(shì)；熒光實(shí)時(shí)定量PCR技術(shù)來測(cè)定噪聲刺激前后Mn-SOD的mRNA在螺旋神經(jīng)節(jié)不同區(qū)域的表達(dá)差異。 3結(jié)果 ABR測(cè)聽結(jié)果顯示：大鼠噪聲暴露后第1、3、14d與暴露前1d相比，4、8、16、20、32kHz的ABR閾值均明顯上移，而且以高頻區(qū)聽閾變化更為顯著；免疫組織化學(xué)染色及western-blot結(jié)果顯示：在正常對(duì)照組中,頂部螺旋神經(jīng)節(jié)的Mn-SOD的表達(dá)較底部明顯；而噪聲暴露后，Mn-SOD在螺旋神經(jīng)節(jié)的表達(dá)較對(duì)照組相應(yīng)部位均顯著增高；且頂部較底部的表達(dá)仍然更為顯著；黃嘌呤氧化酶法Mn-SOD活性測(cè)定結(jié)果顯示：在正常情況下,頂部螺旋神經(jīng)節(jié)的Mn-SOD活性與底部相比無統(tǒng)計(jì)學(xué)差異，，而在噪聲暴露后，Mn-SOD的活性則較對(duì)照組相應(yīng)部位均有降低，而且底部較頂部的變化更為顯著；熒光實(shí)時(shí)定量PCR結(jié)果顯示：在正常情況下,頂部螺旋神經(jīng)節(jié)的Mn-SODmRNA的表達(dá)較底部明顯；而噪聲暴露后，Mn-SODmRNA在螺旋神經(jīng)節(jié)的表達(dá)較對(duì)照組相應(yīng)部位均顯著增高；且頂部仍較底部的表達(dá)量更大。 4結(jié)論 以往研究表明，在噪聲性耳聾的早期，以底回外毛細(xì)胞的損傷為主，而螺旋神經(jīng)節(jié)則沒有發(fā)生明顯的形態(tài)學(xué)改變。然而，我們的研究表明，噪聲刺激同樣在早期既可引起對(duì)螺旋神經(jīng)節(jié)細(xì)胞的氧化應(yīng)激作用，并導(dǎo)致螺旋神經(jīng)節(jié)細(xì)胞內(nèi)相關(guān)的抗氧化酶類表達(dá)水平發(fā)生了改變。而且表現(xiàn)為頂部螺旋神經(jīng)節(jié)細(xì)胞的抗氧化能力顯著高于底部�？寡趸芰Φ膮^(qū)域性差異與噪聲性耳聾的高頻聽力易損性的特點(diǎn)，以及其對(duì)應(yīng)的毛細(xì)胞損傷區(qū)域相一致。這一現(xiàn)象，為今后進(jìn)一步研究噪聲性耳以及聾感音神經(jīng)性聾的氧化損傷機(jī)制及高頻聽力易損性的影響因素提供了新的思路。
[Abstract]:Objective sensorineural deafness is a common disease in otology. Studies have shown that the occurrence of sensorineural deafness is closely related to oxidative injury of sensory neurons in the cochlea. As an important sensory nerve cell in the cochlea, the spiral ganglion cells had no obvious morphological damage in the early stage of sensorineural hearing loss, but they were also affected by oxidative stress. As a result, the expression and properties of oxidative stress related molecules changed. The changes were different in different regions of the spiral ganglion. The regional distribution of antioxidants and the changes of their activities reflect the difference of cell antioxidant capacity in different regions. In this study, we examined the correlation between the expression and activity of antioxidant enzyme manganese superoxide dismutase (Mn-SOD) in mitochondria in different regions of rat spiral ganglion before and after noise stimulation and the high frequency hearing vulnerability. Methods the animal model of noise induced deafness in SD rats was established by giving white noise 115dB2h for 3 consecutive days. ABR audiometry was used to analyze the noise damage at different frequencies. Immunohistochemical staining and western-blot were used to analyze the expression level of Mn-SOD in different regions of spiral ganglion before and after noise exposure, and xanthine oxidase method was used to detect the activity and change trend of Mn-SOD in different regions of spiral ganglion. Fluorescence real-time quantitative PCR was used to detect the difference of Mn-SOD mRNA expression in different regions of spiral ganglion before and after noise stimulation. Results the results of ABR audiometry showed that compared with the first day after noise exposure, the ABR thresholds of the rats at the 1st day after noise exposure were significantly higher than those at the first day before exposure, and the changes of the ABR thresholds in the high frequency region were more significant than those in the first day after noise exposure. Immunohistochemical staining and western-blot results showed that the expression of Mn-SOD in the parietal spiral ganglion was significantly higher than that in the bottom of the control group. After noise exposure, the expression of Mn-SOD in the spiral ganglion was significantly higher than that in the control group, and the expression of Mn-SOD was still more significant at the top than at the bottom. The results of Mn-SOD activity determination by xanthine oxidase method showed that the Mn-SOD activity of the parietal spiral ganglion was not significantly different from that of the bottom under normal conditions, but after noise exposure, there was no significant difference in the activity of Mn-SOD in the parietal spiral ganglion. The activity of Mn-SOD was lower than that of the control group, and the change of the bottom was more significant than that of the top. The results of real-time quantitative PCR showed that the expression of Mn-SODmRNA in the parietal spiral ganglion was significantly higher than that in the bottom, and the expression of Mn-SODmRNA in the spiral ganglion was significantly higher than that in the control group after noise exposure. And the expression at the top is still larger than that at the bottom. Conclusion in the early stage of noise-induced deafness, the damage of outer hair cells in the basal gyrus is the main one, while the spiral ganglion has no obvious morphologic changes in the early stage of noise-induced deafness. However, our studies have shown that noise stimulation can also cause oxidative stress in spiral ganglion cells and change the expression of related antioxidant enzymes in spiral ganglion cells. Moreover, the antioxidation ability of the parietal spiral ganglion cells was significantly higher than that of the bottom. The regional differences in antioxidant capacity are consistent with the characteristics of high frequency hearing vulnerability and the corresponding hair cell damage area of noise-induced deafness. This phenomenon provides a new idea for the further study of oxidative damage mechanism of noise-induced hearing loss and deaf-sensorineural hearing loss and the influencing factors of high-frequency hearing vulnerability.
【學(xué)位授予單位】：第四軍醫(yī)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：R764.431

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 孫國(guó)貴;胡萬寧;王雅棣;李運(yùn)明;景紹武;李成林;崔大為;;MnSOD表達(dá)特性與食管癌細(xì)胞放射敏感性的關(guān)系[J];癌變·畸變·突變;2012年02期

2 丁書茂,楊旭;超氧化物歧化酶及其模擬化合物研究進(jìn)展[J];高等函授學(xué)報(bào)(自然科學(xué)版);2004年01期

3 于紅;祝威;李興啟;;活性氧與內(nèi)耳毛細(xì)胞凋亡相關(guān)的信號(hào)轉(zhuǎn)導(dǎo)及基因調(diào)控[J];國(guó)際耳鼻咽喉頭頸外科雜志;2006年02期

4 高建華;郭艷翔;劉佳賓;王金勝;;杏鮑菇菌絲體中SOD提取方法研究[J];食用菌;2007年02期

5 張俊艷;賀陽;;超氧化物歧化酶研究與應(yīng)用[J];食品工業(yè);2012年03期

6 王昌祿;曹俊武;王玉榮;陳勉華;陳志強(qiáng);田少然;;銅鋅超氧化物歧化酶(SOD)研究進(jìn)展——從基因到功能(英文)[J];現(xiàn)代生物醫(yī)學(xué)進(jìn)展;2008年05期

7 吳雄輝;孫虹;;超氧化物歧化酶與氧化應(yīng)激相關(guān)內(nèi)耳疾病的研究進(jìn)展[J];現(xiàn)代生物醫(yī)學(xué)進(jìn)展;2010年15期

8 劉國(guó)輝,謝鼎華,伍偉景;感音神經(jīng)性聾氧化損傷機(jī)理研究進(jìn)展[J];聽力學(xué)及言語疾病雜志;2005年02期

9 戴德;氧自由基與氨基糖苷類抗生素致聽覺損害的相關(guān)性研究[J];現(xiàn)代預(yù)防醫(yī)學(xué);2005年05期

10 顧含真;陸領(lǐng)倩;袁勤生;趙健;韓瑞貞;周永祥;;超氧化物歧化酶兩種測(cè)活方法的比較[J];藥物生物技術(shù);2006年05期

本文編號(hào)：2380469