经圆窗径路导入正庚醇建立老年性聋模型的实验研究

Experimental Study on Establishment of Presbycusis Model by Introducing N-Heptanol Through Round Window

目的研究经耳后圆窗径路向C57BL/6Cnc小鼠内耳导入正庚醇对其听性脑干诱发电位(ABR)的影响,并建立老年性耳聋模型。方法选取30只健康4周龄C57BL/6Cnc小鼠,随机分成实验组和对照组,每组15只。实验组经耳后圆窗径路缓慢导入正庚醇5μL,对照组经耳后圆窗径路缓慢导入0.9%氯化钠注射液5μL。各组小鼠分别于术前3天、术后2小时、术后1天、术后3天行ABR检测。结果所有实验小鼠无感染迹象,无前庭功能受损表现。对照组小鼠术耳各时间点ABR平均阈值差异无统计学意义(P>0.05),实验组小鼠术耳术后ABR平均阈值显著升高(P<0.05),且随着时间推移呈逐渐增高的趋势,具体数值如下:术前3天、术后2小时、术后1天、术后3天分别为(16.67±2.36)dB、(41.02±4.53)dB、(48.02±2.07)dB、(56.67±2.35)dB。同一时间点实验组小鼠32 kHz频率ABR平均阈值高于12 kHz ABR平均阈值,差异有统计学意义(P<0.05)。结论正庚醇经耳后圆窗径路损伤C57BL/6Cnc小鼠耳蜗后其听觉功能呈逐渐下降改变,成功建立老年性耳聋模型。

Objective To study the effect of n-heptanol introduced into the inner ear of C57BL/6Cnc mice through the round window behind ear on their auditory brainstem response(ABR),and to establish a presbycusis model.Methods 30 healthy 4-week-old C57BL/6Cnc mice were selected and randomly divided into experimental group and control group,with 15 mice in each group.5μL of heptanol was slowly introduced into the experimental group through the round window behind ear,and 5μL of 0.9%sodium chloride injection into the control group.ABR tests were performed on all the mice 3 days before surgery,2 hours,1 day and 3 days after surgery respectiuely.Results All the mice showed no signs of infection or impaired vestibular function.There was no statistically significant difference in the mean ABR threshold at each time point in the operative ears of the mice in the control group(P>0.05),while the mean ABR threshold in the operative ears in the experimental group significantly increased after surgery(P<0.05),showing a gradually increasing trend with the passing of time.Specific values were as follows:the mean ABR threshold 3 days before surgery,2 hours,1 day and 3 days after surgery was(16.67±2.36)dB,(41.02±4.53)dB,(48.02±2.07)dB and(56.67±2.35)dB respectively.The mean ABR threshold of 32 kHz was higher than that of 12 kHz at the same time point in the experimental group,and the difference was statistically significant(P<0.05).Conclusion The auditory function of C57BL/6Cnc mice gradually decreased after being damaged by n-heptanol introduced through the round window,and the presbycusis model has been established successfully.