目的探讨不同浓度ouabain溶液对贵州小型猪内耳的作用,分析听力改变与药物浓度关系。方法采用健康、黑色2月龄贵州小型猪13只,随机分为实验组、对照组和正常对照组,其中试验组动物通过完整圆窗膜局部应用不同浓度ouabain,分为1mM组、0.1mM组,对照组动物局部使用等量生理盐水,正常对照组不予特殊处理。用药前后行听陛脑干反应测定,并通过免疫荧光法,观察各组动物在应用药物后三天、一周、两周时的听功能及内耳形态学(螺旋神经节、毛细胞)的变化。结果生理盐水对照组及正常对照组内耳形态及听功能未见明显变化,不同浓度Ouabain均可导致螺旋神经节细胞数目减少,毛细胞形态及数量与对照组之间无显著性差异,ABR阈值变化明显(P〈0.05)。结论经完整圆窗膜给药,ouabain溶液对小型猪螺旋神经节细胞有损伤,并且损伤程度具有浓度依赖性,并造成听阈明显提高,ouabain对毛细胞的影响不明显。
Objective To investigate the relationship among cochlear morphology, hearing changes and ouabain concen- tration. Method Thirteen healthy, 2-months-old black Guizhou miniature pigs were randomly divided into an experimental group, an experiment control group and a normal control group. Ouabain (200 ul at 1 mM or 0.1 raM) was delivered through in- tact round window membrane. The same volume of saline was administrated to the experiment control group animals through the same pathway. No treatment was applied to the normal control group. Auditory brainstem responses were measured before and after ouabain delivery. The number of spiral ganglion neurons was counted under a microscope. The morphology of hair cells in the organ of Corti was examined after the application of drugs for three days, one week or two weeks. Results There was no significant changes in the morphology of the inner ear and auditory function in the experiment control and normal con- trol groups. After application of ouabain, the number of spiral ganglion cells decreased and the ABR threshold increased signif- icantly (P 〈0.05). The number of hair cells showed no significant change. Conclusion The spiral ganglion neuron can be in- jured and hearing threshold elevated by ouabain delivered through intact round window membrane in a dose and time depen- dent manner. Hairs cells are not significantly affected by ouabain.