亚硒酸钠拮抗庆大霉素所致豚鼠耳蜗毒性实验研究

Experimental Study of Antitoxic Effect of Sodium Selenite on Guinea Pig Cochlea Injury Induced by Gentamicin in Vivo

目的观察亚硒酸钠对庆大霉素所致活体豚鼠耳蜗损害是否具有拮抗作用。方法20只豚鼠随机分为实验组和对照组各10只,给予肌肉注射庆大霉素200mg/kg/d,共8d;实验组同时口服亚硒酸钠1mg/kg/d,共8d。用药前后进行听性脑干反应(ABR)测试观察听功能变化;通过扫描电镜(SEM)及透射电镜(TEM),观察耳蜗形态学变化。结果对照组动物的ABR阈值比实验组高约30dB(P<0.01),Ⅰ波潜伏期较实验组延长约0.23ms(P<0.01);SEM示对照组动物耳蜗外毛细胞纤毛区域性缺失;实验组纤毛形态基本正常;TEM示对照组动物耳蜗外毛细胞线粒体外膜破坏,局部膨出,次级溶酶体增多,可见髓样小体;实验组动物耳蜗外毛细胞基本正常。结论亚硒酸钠对庆大霉素所致活体豚鼠耳蜗损伤有拮抗作用。

Objective To explore the effect of sodium selenite on gentamicin-induced ototoxicity. Methods Twenty guinea pigs were randomly divided into the experimental group and control group with 10 animals in each group. The animals were treated with i. m injection of gentamicin （200 mg/kg/d for 8 consecutive days, and at same time, the experimental group was added with p. o tablet of sodium selenite （1 mg/kg/d）. Before and after the administration, hearing function was evaluated by examination for auditory brain stem responses （ABR）. The cochlear outer haircells were observed by scanning electronic microscope （SEM） and transmission electronic microscope （TEM）. Results ABR threshold of the control group was about 30 dB above that of the experimental group （ P 〈0. 01）. The latency of wave Ⅰ of the control group was about 0. 23 ms above that of the experimental group （ P 〈0.01 ）. Under SEM, the cilia of the majority outer hair cells of the control group lodged even disappeared, while that of the experimental remained regular. Under TEM, in outer hair cells of the control group, mitochondrial crests were obscure, out membrane was damaged and local protruding, the number of secondary lysosornes was increased, myeloid bodies appeared, but in the experimental group, outer hair cells basically remained normal. Conclusion Sodium selenite has antitoxic effect on guinea pig cochlea injury induced by gentamicin in vivo.