胆红素对离体培养大鼠耳蜗基底膜的药理效应观察

Effects of Bilirubin on Cochlear Basilar Membrane in Rats

目的观察胆红素对离体培养的新生SD大鼠耳蜗器官的损伤效应。方法健康新生3日龄SD大鼠18只,雌雄不限,分离其双侧的内耳共得到耳蜗器官组织36个,体外培养,12h后换液。选择贴壁、存活良好的组织30个入选实验,并随机分为两组(15个/组):实验组于贴壁第二天开始进行胆红素处理,对照组加入相应体积的生理盐水。处理后24h,实验组和对照组同时终止培养,并对其进行固定、免疫组织化学染色,共聚焦显微镜观察毛细胞及螺旋神经节神经元的形态变化并计数,统计对比。结果胆红素组离体培养的耳蜗器官中螺旋神经节神经元胞体及其树突纤维与对照组相比有明显的减少,内外毛细胞形态完整,数量无明显变化。结论大鼠耳蜗器官螺旋神经节神经元对胆红素的毒性敏感,而内外毛细胞对其毒性相对不敏感。

Objective To investigate the toxic effects of bilirubin on the cultured P3 rat cochlear in vitro. Methods Thir-ty-six cochlear basilar membranes including spiral ganglion neuron were gently isolated from eighteen healthy P3 Sprague-Dawley （SD） rats of both genders. After 12 hour＇s primary culturing, the culture medium was removed and replaced with 5%FBS fresh medium. 6 samples were not in good survival shape and were discarded.The other 30 samples in good sur-vival shape were randomly divided into two groups （15 each） and treated with normal saline （control group） or bilirubin （experi-mental group） respectively. After 24h’s culture, all the samples in the both groups were fixed and underwent immunofluores-cence staining. The morphology of the SGNs or HCs were observed under laser confocal microscope. The numbers of the nerve fibers and hair cells were counted and underwent statistical analysis. Results The number of the nerve fibers in the experi-mental group were reduced significantly compared with that of the control group. The shape and number of the hair cells （inner or outer） didn＇t change significantly. Conclusion The spiral ganglion neurons are sensitive to bilirubin in vitro but the inner and outer hair cells are not sensitive to bilirubin.