摘要
目的探讨药物致聋后,延迟给予脑源性神经营养因子(brain-drived neurotrophic factor,BDNF)对耳蜗病理及听觉生理的影响。方法药物致聋大鼠20只,随机平均分为人工外淋巴液(artifical perilymph,AP)组和BDNF组。左侧耳蜗为实验侧,右侧耳蜗为对照侧。致聋30天后通过微渗透压泵向鼓阶内持续灌注AP或BDNF,期间进行电诱发听性脑干反应(electrically auditory brainstem response,EABR)阈值检测。持续给药28天后取耳蜗进行病理检查,观察Rosenthal管内螺旋神经节细胞(spiral ganglion cell,SGC)胞体密度及骨螺旋板缰孔内神经纤维密度。结果EABR阈值AP组持续升高,BDNF组阈值初期上升缓慢,后期开始下降,用药治疗14～28夭阈值低于AP组(P<0.01);耳蜗病理变化,SGC胞体密度及神经纤维密度左右侧对比,AP组双侧无差异(P>0.05),BDNF组左侧明显高于右侧(P<0.01);两组左侧比较,BDNF组高于AP组(P<0.01)。结论大鼠药物致聋30天后,鼓阶内BDNF持续给药对SGC胞体及树突均有保护作用,并可以相应改善电听觉敏感性。
OBJECTIVE To determine the influence of delayed intervention of BDNF application on cochlear pathology and auditory physiology after drug induced deafness in rats.METHODS The left cochlea of 20 profound deafness rats,which were divided into 2 groups equally,was implanted with an electrode and drug-delivery system 30 days after deafness.BDNF or artificial perilymph（AP）was delivered continuously for 28 days.EABRs were recorded during the period.Cochleae were harvested for pathology observation.SGC body and peripheral process density were observed.RESULTS EABR thresholds of AP group increase continually.Those of BDNF group increased slowly at beginning,and decreased at last,and were significantly less than those of AP group from day 14 to 28 0.01）.In terms of SGC and peripheral process density,the difference between the treated and control ears of BDNF group was clearly significant（P〈0.01）,but not in AP group （P〉0.05）.Analysis of the left cochlea between the two groups demonstrated that SGC and peripheral process density of BDNF group was significantly greater than that of AP group.CONCLUSION Under the condition of delayed application of BDNF through tympanic scala following drug induced deafness in rats,BDNF can enhance SGC body and peripheral process survival and improve auditory sensitivity.
出处
《中国耳鼻咽喉头颈外科》
北大核心
2008年第10期562-565,共4页
Chinese Archives of Otolaryngology-Head and Neck Surgery
基金
国家自然科学基金项目(30572028)
北京市自然科学基金项目(7032008)
北京市科技新星计划(9558101300)联合资助
