卡那霉素和速尿联合用药后的毛细胞死亡

The Death Duration and Model of Cochlear Hair Cells in Guinea Pigs after the Combined Administration of Kanamycin and Furosemide

目的观察卡那霉素和速尿联合用药后豚鼠耳蜗毛细胞的死亡时程和方式.方法选用健康成年白色红目豚鼠,雌雄不限,随机分成健康对照组和药物致聋后6 h、9 h组（实验组）,每组5只.实验组在选取的时间点完成听性脑干反应（ABR）检测后行耳蜗基底膜铺片、PI荧光染色,共聚焦显微镜下观察毛细胞.对照组不做处理.结果实验组半数豚鼠致聋（ABR阈值〉95 dB SPL）,致聋豚鼠耳蜗可见外毛细胞核固缩和核肿胀,与给药6 h组相比,给药9 h组外毛细胞核肿胀数目增多.检测给药6 h组和9 h组豚鼠末端脱氧核苷酸转移酶介导的dUTP缺口末端标记物（terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling,TUNEL）,没有观察到阳性着色细胞.正常对照组所有豚鼠ABR正常,其耳蜗各回毛细胞没有出现毛细胞核固缩或者核肿胀.结论卡那霉素和速尿联合用药后数小时即可导致豚鼠耳蜗毛细胞死亡,毛细胞损害为两种类型,即坏死和凋亡.

Objective To observe the death duration and model of cochlear hair cells in guinea pigs after the administration of kanamycin and Furosemide. Methods Healthy adult white guinea pigs with red eyes were randomly selected without consideration of gender. These guinea pigs were randomly divided into 3 groups with 5 guinea pigs in each group, i.e. control group, 6 h after drug administration group and 9 h after drug administration group. After receiving ABR test at specific time, the cochlear basilar membrane of the experimental group was processed by stretched preparation technique and treated with fluorescent staining. The hair cells were observed under the confocal microscope. The control group was untreated. Results Half of the experimental group had hearing loss induced by kanamycin and furosemide （ABR threshold〉 95 dB SPL）. The cochlear outer hair cells of the guinea pigs showed nuclear pyknosis and swelling. There were more cells with swelling nucleus in the group 9 h after drug administration than the group 6 h after administration. No positive cell can be detected with the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling （TUNEL） methods in groups 6 and 9 h after drug administration. The ABR thresholds were normal and neither nuclear pyknosis nor nuclear swelling can be seen in the cochlear hair cells of the control group. Conclusion The combined administration of the kanamycin and furosemide can induce the death of cochlear hair cells in guinea pigs several hours later and the hair cells are damaged in two ways, i.e. necrosis and apoptosis.