不同剂量白喉毒素对野生型听力成熟小鼠耳蜗结构及听功能的影响

发布时间：2018-02-04 12:49

本文关键词： 白喉毒素耳毒性白喉毒素受体　出处：《听力学及言语疾病杂志》2017年04期 　论文类型：期刊论文

【摘要】：目的观察不同剂量白喉毒素对野生型听力成熟小鼠的耳蜗结构及听功能的影响,为建立白喉毒素受体介导的细胞敲除系统动物模型提供参考。方法 4周龄C57BL/6J小鼠30只随机分为50ng/g组、100ng/g组和对照组,每组10只;其中50ng/g组和100ng/g组小鼠分别单次腹腔注射白喉毒素50ng/g、100ng/g,对照组小鼠单次腹腔注射等量生理盐水,注射后7天观察两组动物的一般情况,并记录小鼠ABR反应阈,观察小鼠内外毛细胞、螺旋神经节神经元。结果在白喉毒素注射后第7天,各组动物情况良好,无明显体重下降,中耳腔无积液。50ng/g组小鼠2、8、32kHz ABR反应阈分别为57.5±2.74、20.83±2.04、45.83±2.04dB SPL,与对照组比较(分别为56.25±2.31、20.0±3.78、49.38±6.78dB SPL)差异无统计学意义;内、外毛细胞损失率分别为0.8%±0.5%、1%±0.6%;对照组分别为0.3%±0.5%、0.4%±0.3%;螺旋神经节神经元SGN密度为39.45±3.65个/105μm2、对照组为41.03±3.73个/105μm2,均未见明显细胞缺失。100ng/g组小鼠2、8、32kHz ABR反应阈分别为85±3.54、63±4.47、90±0dB SPL,较前两组显著升高(t=19.62,P0.001),内、外毛细胞损失率分别为0.5%±0.1%、10.7%±0.3%,损伤严重,底、中、顶回缺失达10%(t=42.219,P0.001);SGN密度为25.55±3.66个/105μm2,平均减少38%,与对照组相比差异有显著统计学意义(t=10.985,P0.001)。结论 100ng/g白喉毒素注射能引起听力成熟野生型C57BL/6J小鼠外毛细胞及螺旋神经元的损伤。
[Abstract]:Objective to observe the effects of diphtheria toxin at different doses on cochlea structure and auditory function in wild type hearing mature mice. Methods Thirty 4-week-old C57BL / 6J mice were randomly divided into 50 ng / g group. 100 ng / g group and control group, 10 rats in each group; The mice in 50 ng / g group and 100 ng / g group were given diphtheria toxin 50 ng / g / g intraperitoneally respectively, and the control group were injected with the same amount of normal saline once. The general situation of the two groups was observed 7 days after injection, and the ABR reaction threshold was recorded, and the inner and outer hair cells and spiral ganglion neurons of the mice were observed. Results on the 7th day after diphtheria toxin injection, the mice were treated with diphtheria toxin. The animals in each group were in good condition and had no significant weight loss. The reaction threshold of the mice in the middle ear cavity without effusion. 50 ng / g group was 57.5 卤2.74 at 832kHz ABR, respectively. 20. 83 卤2. 04 卤45. 83 卤2. 04 dB SPLs were compared with the control group (56.25 卤2.31) and 20.0 卤3.78, respectively. 49.38 卤6.78dB SPLs had no statistical significance. The loss rate of inner and outer hair cells was 0.8% 卤0.5% 卤0.6%, respectively. The control group was 0.3% 卤0.5% 卤0.3%; The SGN density of spiral ganglion neurons was 39.45 卤3.65 / 105 渭 m ~ (2), and that of control group was 41.03 卤3.73 / 105 渭 m ~ 2. The reaction threshold of 32kHz ABR was 85 卤3.54 卤4.47 卤90 卤0 dB SPL in the mice in the 100ng / g group. Compared with the former two groups, the loss rate of outer and inner hair cells was 0.5% 卤0.1% 卤0.3%, respectively, which was significantly higher than that of the former two groups. The absence of parietal gyrus was 42.219m (P 0.001); The density of SGN was 25.55 卤3.66 / 105 渭 m ~ (2), with an average decrease of 38 ~ (th). The difference was statistically significant compared with that of the control group (10.985). Conclusion 100 ng / g diphtheria toxin injection can cause damage to outer hair cells and spiral neurons of mature wild-type C57BL / 6J mice.
【作者单位】：第六人民医院耳鼻喉科研究所上海交通大学附属第六人民医院;
【基金】：上海市人才发展基金资助项目(201613)
【分类号】：R764
【正文快照】： 网络出版地址:http://kns.cnki.net/kcms/detail/42.1391.R.20170630.0951.004.html白喉毒素是由白喉杆菌分泌的外毒素,当其与白喉毒素受体结合后,白喉毒素被细胞内吞,抑制真核生物蛋白合成延长因子2的活性,从而抑制该细胞蛋白合成,诱发细胞凋亡。近年来,由白喉毒素受体介导的

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