Shi Q Y
First Affiliated Hospital, Shanxi Medical College, Taiyuan.
Zhonghua Er Bi Yan Hou Ke Za Zhi. 1993;28(6):344-5, 381.
Forty-five guinea pigs were randomly divided into 2 groups: 15 in the control group and 30 in the experimental group. All animals were injected immediately with 400 mg/kg kanamycin for 10 days. At the same time, the experimental animals were given orally 10 mg/kg thyroxin every other day 5 times. All animals were decapitated 10 days after administration of drugs and measurement of ABR. Then, the specimens of cochlea were prepared for both SEM and TEM. The result of SEM showed that the degeneration and loss of stereocilium in each turn was significantly milder in the experimental group than in the control. Under TEM, outer and inner hair cells showed changes caused by kanamycin. In the experimental group, the mitochondrias were basically normal. The secondary lysosomes gathered under cuticular plate and supranuclear area. In the control group, the mitochondria showed pyknosis and high density, and multivesicular bodies were increased. The cytoplasm was swelling. There were many vacuoles produced by accumulation of liquid in the cytoplasm. Based on the findings of ultrastructural changes of cochlear hair cells, the mechanism of thyroxine against ototoxicity of kanamycin was discussed.
45只豚鼠被随机分为2组：对照组15只，实验组30只。所有动物立即注射400mg/kg卡那霉素，持续10天。同时，实验组动物每隔一天口服10mg/kg甲状腺素，共5次。给药及测量听性脑干反应（ABR）10天后，所有动物断头。然后，制备耳蜗标本用于扫描电子显微镜（SEM）和透射电子显微镜（TEM）观察。SEM结果显示，实验组各圈毛细胞静纤毛的退变和丢失明显轻于对照组。在TEM下，外毛细胞和内毛细胞均显示出卡那霉素引起的变化。实验组线粒体基本正常。次级溶酶体聚集在表皮板和核上区域下方。对照组线粒体显示核固缩和高密度，多囊体增加。细胞质肿胀。细胞质中有许多因液体蓄积而产生的空泡。基于耳蜗毛细胞超微结构变化的研究结果，探讨了甲状腺素对抗卡那霉素耳毒性的机制。
