卡铂引起的灰鼠耳蜗内毛细胞缺损模式

目的:研究卡铂损害灰鼠耳蜗内毛细胞(IHCs)的模式,即IHCs何时出现缺损、给药后不同时间基底膜上IHCs缺损的范围、基底膜上IHCs 最大缺损部位以及致绝大部分IHCs缺损所需时间等。方法:对成年灰鼠采用一次性卡铂腹腔注射(100mg／kg),给药后不同时间处死动物,常规制备耳蜗铺片和耳蜗图,以定量观察灰鼠耳蜗毛细胞的缺损情况。结果:注射卡铂后从24h-3个月,灰鼠的外毛细胞基本无缺损。IHCs损伤模式的特征:①注射卡铂后24h耳蜗毛细胞完整无损,IHCs从注药后第3天开始出现缺损;②从注射卡铂后3d到3个月期间,IHCs的最大缺损率均出现在第一回和第二回交界处;③ IHCs缺损从第1回和第2回交界处开始,范围逐渐向底回和顶回扩展, 与顶回相比,底回的IHCs缺损出现早且更严重;④至注射后3个月基底膜上IHCs的缺损呈平坦型。结论:100mg／kg卡铂腹腔注射对各回IHCs的破坏是不均等的,对卡铂的敏感度不一致可能造成了各回 IHCs缺损在时间上的差异。图4参16     

卡铂引起的灰鼠耳蜗内毛细胞缺损模式

目的:研究卡铂损害灰鼠耳蜗内毛细胞(IHCs)的模式,即IHCs何时出现缺损、给药后不同时间基底膜上IHCs缺损的范围、基底膜上IHCs最大缺损部位以及致绝大部分IHCs缺损所需时间等。方法:对成年灰鼠采用一次性卡铂腹腔注射(100mg/kg),给药后不同时间处死动物,常规制备耳蜗铺片和耳蜗图,以定量观察灰鼠耳蜗毛细胞的缺损情况。结果:注射卡铂后从24h～3个月,灰鼠的外毛细胞基本无缺损。IHCs损伤模式的特征:①注射卡铂后24h耳蜗毛细胞完整无损,IHCs从注药后第3天开始出现缺损;②从注射卡铂后3d到3个月期间,IHCs的最大缺损率均出现在第1回和第2回交界处;③IHCs缺损从第1回和第2回交界处开始,范围逐渐向底回和顶回扩展,与顶回相比,底回的IHCs缺损出现早且更严重;④至注射后3个月基底膜上IHCs的缺损呈平坦型。结论:100mg/kg卡铂腹腔注射对各回IHCs的破坏是不均等的,对卡铂的敏感度不一致可能造成了各回IHCs缺损在时间上的差异。     

DPOAE监测一次性大剂量顺铂致豚鼠耳毒性的实验研究

目的观察一次性大剂量顺铂注射后豚鼠畸变产物耳声发射(DPOAE)和内耳形态学的依时性改变,探讨应用耳声发射监测顺铂耳毒性的最佳时机。方法将豚鼠随机分为对照组(A组)及实验组(B、C、D组),每组6只,A组皮下注射生理盐水,B、C、D各组一次性皮下注射顺铂(10mg/kg),分别于给药前及给药后第3(B组)、5(C组)、10(D组)天检测DPOAE,比较给药前、后DPOAE的幅值的变化,并行耳蜗铺片,观察毛细胞缺失率及耳蜗形态学的改变。结果给药后第3天,DPOAE的幅值仅8kHz处有明显改变(P<0.05);给药后第5、10天DPOAE幅值明显降低(P<0.01)。给药后第3、5、10天,耳蜗外毛细胞缺失率分别为4.34%±3.20%、16.14%±9.15%、18.25%±9.04%。在第5、10天后尚可见血管纹充血以及螺旋神经节细胞肿胀缺失。结论顺铂的耳毒性主要作用于耳蜗底回、中回的外毛细胞,用药后第3~5天应用畸变产物耳声发射检查能早期发现其耳毒性损伤。     

内毛细胞缺损对噪声引起外毛细胞损害的潜在影响

目的　观察噪声对正常灰鼠和内毛细胞缺损灰鼠的外毛细胞是否具有不同的破坏效应。方法　 6只正常灰鼠和 12只卡铂致聋灰鼠作为受试对象。提前 30天给 12只灰鼠按照 10 0mg/kg的剂量腹腔注射卡铂 ,以达到预先选择性破坏其内毛细胞的目的。将 6只正常灰鼠和 6只经卡铂处理的灰鼠移入噪声室 ,在强度为 12 0dB、中心频率在 4kHz的脉冲噪声环境暴露 6小时 ;另外 6只经卡铂处理的灰鼠不经噪声暴露作为对照组。在噪声暴露后 30天取出耳蜗 ,常规制备耳蜗铺片 ,然后进行全耳蜗毛细胞计数 ,并将各组动物的毛细胞计数结果制备成平均受损情况分布图 ,观察和比较噪声引起的外毛细胞损害水平在具有正常内毛细胞的灰鼠和丧失内毛细胞的灰鼠是否存在差别。结果　单纯注射卡铂的灰鼠内毛细胞平均损失在 90 %左右 ,但外毛细胞无损害。经噪声暴露的正常灰鼠外毛细胞在耳蜗底回中部约相当于 4kHz共振频率区域平均损失 6 0 % ,但是在该区域两侧靠近底回和顶回的外毛细胞损失少于 2 0 %。预先经卡铂破坏 95 %内毛细胞的灰鼠经噪声暴露后 ,外毛细胞在耳蜗底回中部平均损失达到 90 % ,在该区域两侧的外毛细胞损失百分比大于 4 0 %。结论　内毛细胞缺损可以造成更多的外毛细胞在噪声刺激中被破坏 ,提示正常内毛细胞的存在可能有     

顺铂对离体C57小鼠耳蜗毛细胞的损害作用

目的探讨离体培养条件下顺铂致C57小鼠耳蜗毛细胞损伤的特点。方法出生后3～4天的C57小鼠耳蜗基底膜离体培养6～8小时后,加入不同浓度的顺铂（0、10、50、100、400、1000μmol/L）无血清培养液继续培养48小时,其中0μmol/L为正常对照组,10～1000μmol/L组为实验组,0～100μmol/L4组,每组各7只耳蜗,400和1000μmol/L两组各6只耳蜗。采用TRITC-Phalloidin和DAPI染色,荧光显微镜下观察耳蜗毛细胞生长情况并拍照计数、绘制毛细胞缺失图,运用SARS8.0软件进行直线回归分析比较各组的毛细胞缺失率。结果对照组耳蜗基底膜毛细胞在离体培养条件下生长良好,偶见缺失。实验组中顺铂引起毛细胞的缺失程度从底回至顶回大致均匀。随着顺铂浓度从10μmol/L增加到100μmol/L,毛细胞的缺失率从14.5%上升到78.4%;顺铂浓度升高至400μmol/L及1000μmol/L时,毛细胞缺失率下降至48.8%和8.77%。细胞缺失区域可见DAPI着色的浓缩核。结论离体培养条件下,顺铂对耳蜗毛细胞的损伤在一定浓度范围内呈剂量依赖性,超过一定剂量后顺铂所致毛细胞损伤又逐渐减少;内外毛细胞的损伤从底回至顶回呈现均一性。     

α—硫辛酸对庆大霉素所致大鼠耳毒性损害的保护作用

目的 探讨高效抗氧剂α-硫辛酸是否对庆大霉素所致的大鼠耳蜗毒性有防护作用.方法 将30只Wistar大鼠随机分成庆大霉素(GM)组、α-硫辛酸(α-LA)+庆大霉素(GM)组及正常对照组,GM组每日腹腔注射GM100mg/kg;GM+α-LA组每日同时腹腔注射GM100mg/kg和α-LA注射液10mg/kg;正常对照组每日腹腔注射生理盐水100mg/kg.3组皆连续用药10d,用药前后测试DPOAE.最后将动物处死,取听泡,观察毛细胞形态.实验数据进行统计学分析.结果 DPOAE停药后,GM+α-LA组DPOAE幅值有轻度降低;GM组DPOAE幅值明显降低; 2组用药前后比较有显著性差异(P<0.01).GM+α-LA组大鼠听功能受损程度明显轻于GM组.正常对照组大鼠用药前后DPOAE幅值及形态学无明显变化.形态学观察:给药后GM组耳蜗底回外毛细胞均有较重损伤,前庭毛细胞空泡样改变,纤毛倒伏缺失明显.GM+α-LA组耳蜗底回外毛细胞损伤明显减轻,前庭毛细胞散在缺失.正常对照组耳蜗底回外毛细胞和前庭毛细胞基本正常.结论 在使用GM的同时联合应用α-LA可有效减少GM对大鼠的内耳毒性.     

对灰鼠延迟性神经元死亡模型中螺旋神经节细胞缺损的评估

目的探索观察耳蜗螺旋神经节细胞的简便定量研究方法 ,并在灰鼠延迟性螺旋神经节细胞死亡动物模型中验证本方法的实用性和可靠性。方法 15只成年灰鼠平均分为3组,第1组用于正常对照;第2组一次性同时肌肉注射庆大霉素（125mg/kg）和静脉注射利尿酸钠（40mg/kg）,并在用药后2个月处死;第3组接受与第2组同样的药物注射,但在用药后4个月处死。耳蜗样品被常规应用环氧树脂包埋并制作成耳蜗中轴半薄切片,计数耳蜗各回蜗轴螺旋管腔切片截面内的螺旋神经节数量并进行统计分析。结果灰鼠耳蜗底回起始端的蜗轴螺旋管腔比耳蜗底回中部和耳蜗中回大,因此耳蜗底回起始端蜗轴螺旋管内的螺旋神经节细胞数量多于耳蜗底回中部和耳蜗中回。耳蜗毛细胞被彻底破坏后2个月,与正常灰鼠耳蜗各回蜗轴螺旋管腔切片截面内的螺旋神经节细胞数量相比,耳蜗底回蜗轴螺旋管切片截面内的螺旋神经节细胞减少数量比耳蜗中回严重,提示延迟性螺旋神经节细胞死亡可能遵循着从耳蜗底回向顶回扩展的规律。耳蜗毛细胞被彻底破坏后4个月,全耳蜗蜗轴螺旋管内的螺旋神经节细胞基本上丧失殆尽。结论计数耳蜗中轴切片各回蜗轴螺旋管腔切片截面内的螺旋神经节细胞数量是一种简便可靠的定量分析方法 。     

C57BL/10J小鼠内耳形态学观察

目的 探讨不同月龄C57BL／10J小鼠内耳形态学变化。方法 取C57BL/10J小鼠2月龄3只（6耳）、8月龄3只（6耳）、12月龄2只（4耳）、27月龄2只（4耳），采用耳蜗铺片和耳蜗图技术，观察耳蜗和前庭毛细胞的变化。结果 2月龄鼠在耳蜗底回和顶回可见有少量的外毛细胞缺失，内毛细胞正常。8月龄鼠外毛细胞缺失主要由耳蜗底回向顶回发展，少量内毛细胞缺失主要在耳蜗底回，对应于20kHz的基底膜区域显示外毛细胞缺失在20％左右。12月龄鼠外毛细胞缺失明显加重，耳蜗底回部分几乎完全缺失，外毛细胞损失区域发展到基底膜中部，并且蜗尖区域外毛细胞缺失达到40％，耳蜗底回内毛细胞缺失达到60％～80％，蜗尖部分内毛细胞基本正常，对应于20kHz的基底膜区域显示外毛细胞缺失近80％，内毛细胞缺失近30％。27月龄鼠耳蜗外毛细胞从基底膜中部至底回完全缺失，顶回缺失60％～80％，内毛细胞缺失逐渐向蜗尖扩展，对应于20kHz的基底膜区域显示外毛细胞完全缺失，内毛细胞缺失超过50％。前庭选取球囊斑，椭圆囊斑和壶腹嵴三个部位进行观察，不同月龄的C57BL／10J鼠前庭毛细胞均正常。结论 本研究首次对C57BL／10J小鼠的内耳形态学进行观察，发现该鼠同C57BL／6J小鼠比较在外毛细胞缺失规律和时间上有明显的差别，明确了内耳毛细胞的变化规律；同时首次观察了前庭毛细胞，为C57BL／10J小鼠作为遗传性和老年性聋研究的动物模型提供了形态学理论依据。     

灰鼠耳蜗毛细胞脱氢酶活性在卡铂耳中毒时的早期变化

采用组织化学技术观察了灰鼠耳蜗毛细胞中脱氢酶在卡铂耳中毒早期的活性变化.发现卡铂可选择性地抑制内毛细胞中的脱氢酶活性.并且这种影响是从底回开始向顶回发展.提示在内毛细胞变性之前.卡铂可通过抑制内毛细胞的脱氢酶干扰其能量的代谢.     

离体培养时bFGF对顺铂耳蜗毒性的拮抗作用

目的 研究不同浓度的顺铂对耳蜗基底膜毛细胞的损伤、不同浓度的bFGF对顺铂耳蜗基底膜毛细胞损伤的保护作用以及caspase-9的表达。方法 对耳蜗基 底膜进行离体培养,用荧光染色方法对毛细胞数量和caspase-9的表达进行观察。结果 在不同浓度中,15μg/ml顺铂对基底膜毛细胞损伤最大;bFGF浓度≥100ng/ml时,对顺铂所致的基底膜毛细胞损伤具有良好的拮抗作用。结论 顺铂对耳蜗基底膜上毛细胞的损伤具有剂量依赖性; bFGF拮抗顺铂所致的耳蜗基底膜毛细胞的损伤;caspase-9的表达与bFGF对顺铂耳蜗毒性的拮抗作用相关。     

Chinchilla models of selective cochlear hair cell loss

Although it is well known that ethacrynic acid (EA) can enhance gentamicin (GM) ototoxicity, there has been no systematic study of the relationship between dosing parameters and inner ear pathology. We examined the effects of two parameters, GM dose and time delay between GM and EA administration, on cochlear and vestibular hair cell loss in chinchillas. 'No delay' groups received one injection of GM (125, 40, 20, or 10 mg/kg i.m.) followed immediately by EA (40 mg/kg i.v.); 'delay' groups received GM (10 mg/kg i.m.) followed by EA 1 or 1.5 h later. Animals were sacrificed 7 days later for evaluation of hair cell loss in the cochlea and vestibular end organs (cristae, saccule and utricle). Vestibular function was assessed prior to sacrifice by measuring the duration of nystagmus induced by cold caloric stimulation. No delay groups had approximately 100% loss of outer hair cells and dose-dependent losses of inner hair cells, ranging from approximately 100% to 58%. In 1 and 1.5 h delay groups, inner hair cell losses were approximately 19% and 0%, outer hair cell losses were approximately 74% and 47%, and outer hair cell loss followed a typical base to apex gradient. Two results were remarkable. First, the three groups with partial inner hair cell loss showed an atypical lesion pattern in which losses were substantially greater in the apical half than in the basal half of the cochlea. Second, there was no vestibular pathology in any group. The results establish dosing parameters that can be used to produce animal models with defined patterns and magnitudes of cochlear hair cell damage, but normal vestibular function and morphology.     

纯中药制剂复聪汤对庆大霉素致聋豚鼠耳蜗毛细胞修复再生的实验研究

目的观察纯中药制剂对庆大霉素致聋动物和耳蜗毛细胞的修复再生作用。方法选用73只健康青年豚鼠,行听力学检查后,53只动物连续肌肉注射庆大霉素(80mg.kg-1.d-1)24～30天致聋(GM组),其间死亡8只,剩余45只随机分成中药治疗组(25只)和致聋后对照组(20只),中药治疗组给予纯中药制剂"复聪汤Ⅰ号"口服液和"复聪汤Ⅱ号"滴耳液治疗,致聋后对照组同法给予生理盐水。另外20只豚鼠作为正常对照组,每天肌肉注射等量生理盐水。在治疗30、60和90天后对GM组两组动物分别行ABR、DPOAE检测,同时,每一时间点处死6只动物,左侧耳蜗行扫描电镜观察,右侧耳蜗铺片行光镜观察和毛细胞计数。结果实验前所有豚鼠的听功能正常;连续注射庆大霉素30天后,GM组豚鼠ABR反应阈值上升到50～80dB SPL,DPOAE幅值降低,光镜和电镜下表现为耳蜗毛细胞纤毛断碎、倒伏、融合和消失,多处毛细胞表皮板肿胀、突起和疱疹样变性,或毛细胞被完全挤出网状板,基底回和第三回耳蜗毛细胞严重消失;中药治疗30天后,80%的耳聋豚鼠的ABR反应阈恢复到30～50dB SPL,DPOAE幅值明显提高;耳蜗铺片和电镜观察显示耳蜗毛细胞数目有一定恢复,组织结构有修复现象,扫描电镜可见再生毛细胞仅出现少量纤毛,而致聋后对照组未发现此种现象;治疗60天后,耳蜗毛细胞数目明显增多,Corti器的毛细胞区有大量的增殖细胞出现,扫描电镜可见成小束的新生纤毛出现在毛细胞缺失部位,同时支持细胞大量增殖;治疗90天后,再生的静纤毛束已基本形成,尤其是耳蜗基底部位的毛细胞明显增多,听功能基本正常。结论纯中药制剂复聪汤对庆大霉素致聋豚鼠耳蜗毛细胞有一定的修复和再生作用。     

Cisplatin-induced increases in spontaneous neural activity in the dorsal cochlear nucleus and associated outer hair cell loss

Tinnitus is one of the consequences of cisplatin chemotherapy, but its underlying mechanisms are not well understood. Since it has been shown that cisplatin causes outer hair cell loss, it is possible that loss of these cells might induce tinnitus by increasing spontaneous activity in the central auditory system. To test this possibility, the present study examined the effects of cisplatin treatment on cochlear hair cells and on spontaneous neural activity in the dorsal cochlear nucleus of hamsters. Recordings, carried out approximately 1 month after cisplatin treatment, demonstrated significant increases in spontaneous activity across broad regions of the dorsal cochlear nucleus relative to levels in saline-treated controls. Histological results showed that cisplatin-treated animals also displayed dramatic loss of outer hair cells over most of the basal turn of the cochlea. Inner hair cells remained intact, although some evidence of damage to their stereocilia was evident. These findings indicate that cisplatin treatment causes abnormalities in spontaneous activity in the dorsal cochlear nucleus that are associated with widespread damage to outer hair cells. However, since some damage to inner hair cells was also observed, the role of inner hair cell injury in contributing to higher spontaneous activity cannot be ruled out.     

Vestibular destruction by slow infusion of gentamicin into semicircular canals

Intratympanic or round window application of gentamicin is often used to alleviate disabling vertigo arising from unilateral Meniere's disease; however, treatment is often accompanied by hearing loss because the drug initially enters the cochlea before diffusing to the vestibular system. In order to enhance vestibular damage and reduce the risk of hearing loss, gentamicin was infused directly into the vestibular system. An osmotic pump containing 50, 100, 200 or 400 microg/ml of gentamicin was infused into the superior semicircular canal of the chinchilla for 7 days. Afterwards, vestibular damage was evaluated by measuring the decline in hair cell density in the utricle, saccule and superior semicircular canals. Auditory damage was assessed with distortion product otoacoustic emissions (DPOAE) and outer hair cell (OHC) and inner hair cell (IHC) loss. Infusion with the two lowest gentamicin concentrations resulted in significant hair cell loss and reduced duration of the nystagmus response, but had little or no effect on OHC or DPOAE. Higher doses of gentamicin damaged cochlear hair cells and reduced the DPOAE. In conclusion, slow infusion of a low dose of gentamicin into the semicircular canals mainly damages the vestibular hair cells and inactivates the nystagmus response without damaging cochlear hair cells or DPOAE.     

卡那霉素联合呋塞米快速诱导小鼠耳蜗损伤

目的 探讨卡那霉索和呋塞米联合应用对小鼠耳蜗的毒性作用,建立一种可靠的小鼠感音神经性聋模型.方法 选用3～4周龄的CBA/J小鼠为实验对象,按1 g/kg的剂量皮下注射卡那霉素,30～45 min后按0.4 g/kg的剂量腹腔注射呋塞米.在注射前、注射后12 h、24 h、48 h、7 d、2周、4周及12周分别应用听性脑干反应(ABR)检测小鼠听觉功能的改变;应用异硫氰酸荧光素标记的鬼笔环肽及碘化丙啶染色、半薄切片甲苯胺蓝染色、脱氧核苷酸末端转移酶介导的dUTP缺口末端标记技术、扫描电镜等观察小鼠毛细胞死亡的模式和程度;同时通过透射电镜观察记录耳蜗血管纹形态及厚度的变化.结果 序贯应用卡那霉素及呋塞米后12 h小鼠ABR阈值开始上升,随后的36 h内持续进行性上升,继而稳定在90 dB左右.应用激光共聚焦显微镜在药物注射后12 h观察到耳蜗底回外毛细胞开始出现死亡,24 h时底回外毛细胞基本全部消失,同时顶回外毛细胞开始出现死亡,至48 h时整个耳蜗外毛细胞绝大部分死亡;而内毛细胞的损伤至给药后7 d时才开始出现,随时间推移仍有部分内毛细胞完好无损.死亡的毛细胞均具有典型的凋亡细胞特征.扫描电镜观察发现在药物注射后受损毛细胞出现纤毛消失、表皮板塌陷,随后支持细胞增生并在该处形成瘢痕.血管纹表面边缘细胞在给药后出现部分胞体融合并且有坏死物自胞内排出,随后边缘细胞表面大部分微绒毛消失,胞体呈"石块"样改变.透射电镜结果 显示血管纹厚度在给药后进行性下降,主要为边缘细胞萎缩造成.结论 单次序贯应用卡那霉素及呋塞米能快速诱导小鼠耳蜗毛细胞大量死亡,适合应用于建立小鼠感音神经性聋模型.     

全耳蜗毛细胞定量分析系统

目的 介绍一种计算机辅助下的全耳蜗毛细胞定量分析系统。方法 选取氨基糖甙类药物损伤、噪声性损伤以及老年性聋动物模型的耳蜗制备全耳蜗基底膜铺片，从蜗尖向蜗底逐个视野依次进行内外毛细胞计数，将采集的数据输入到计算机并用毛细胞定量分析系统制备成耳蜗图。结果 氨基糖甙类药物耳蜗损害模型的耳蜗图显示毛细胞缺损自底回向顶回发展，外毛细胞的损伤比内毛细胞严重；强噪声引起的毛细胞破坏局限在与刺激声频率相对应的基底膜区域；6月龄C57BL／6J小鼠的耳蜗图显示老年性聋的早期损害起始于耳蜗底回的起始端，其中外毛细胞的破坏比内毛细胞严重。结论 耳蜗毛细胞定量分析系统可清晰显示全耳蜗毛细胞在基底膜上不同部位的损失程度和破坏范围，并可对应到基底膜上各个频率敏感部位。将传统的耳蜗铺片与计算机技术相结合制备的耳蜗图，具有全面可靠、简便精确、规范等优点。     

听神经病的听功能状态分析

目的 :探讨听神经病的听功能状态及病损部位。方法 :分析 6 5例听神经病患者的临床资料、纯音测听、声导抗测试、听性脑干反应 (ABR)、4 0Hz听觉相关电位及OAE检查结果。结果 :听神经病的低频听力损失源于蜗后的传入、传出神经及听性脑干受损 ,表现为声反射、传出抑制、ABR异常及诱发性OAE与纯音听阈不呈平行关系 ,与之相对应 ,低频区的外毛细胞处于失抑制的超常活动状态 ,表现为低频区SOAE增强、TEOAE反应幅值及DPOAE幅值升高 ;听神经病的高频听力损失源于耳蜗的外毛细胞损害 ,表现为高频区DPOAE幅值与纯音听阈呈一致性下降 ;听神经病的中频听力损失最轻或接近正常 ,表现为 2kHz附近的纯音听阈和DPOAE幅值均接近于正常。结论 :听神经病的传入、传出系统及耳蜗水平均有不同程度的功能障碍 ,其病损部位主要在耳蜗传入、传出神经 ,向上可侵及脑干 ,向下可侵及耳蜗     

蛋氨酸对离体培养小鼠耳蜗毛细胞顺铂耳毒性的拮抗作用

目的 在培养基中加入顺铂,建立离体培养小鼠耳蜗毛细胞的顺铂损害模型,探讨蛋氨酸对毛细胞的保护作用.方法 32只出生后2 d昆明小鼠,取出耳蜗基底膜,分为4组,每组16个样本,分别用无血清培养液、含顺铂的无血清培养液、含顺铂+蛋氨酸的无血清培养液以及含蛋氨酸的无血清培养液进行离体培养.采用肌球蛋白Ⅵ(myosinⅥ)免疫荧光染色,通过激光共聚焦显微镜、光镜、毛细胞计数等方法,观察蛋氨酸对顺铂引起的耳蜗毛细胞损伤的保护作用.结果 对照组和蛋氨酸组基底膜内、外毛细胞未见损伤缺失;顺铂组耳蜗基底膜内、外毛细胞均有不同程度的损伤,与对照组和蛋氨酸组比较,差异均具有统计学意义(P值均＜0.05);顺铂+蛋氨酸组基底膜内、外毛细胞的损伤程度与顺铂组相比明显减轻,差异具有有统计学意义(t内毛细胞=3.929、t外毛细胞=8.582,P值均＜0.05).结论 顺铂能损伤离体培养的小鼠耳蜗基底膜毛细胞,蛋氨酸可以在一定程度上拮抗顺铂对毛细胞的损伤.

Abstract：

Objective To establish an in vitro model of mouse cochlear basilar membrane impairment using cisplatin, and observe the protective effect of methionine on the hair cells. Methods The cochlear basilar membrane samples of thirty two Kunming mice were harvested on the 2nd day after birth and randomly divided into four groups. Each group had 16 samples. Overnight preincubation the cochlear organ followed by appropriate treatment respectively as follows: the serum-free culture medium, the serum-free culture medium with methionine and cisplatin, the cisplatinum-containing serum-free culture medium, and the methionine-containing serum-free culture medium. The protective effect of methionine for injury of cochlea hair cells induced by cisplatin was observed by myosin-Ⅵ immunofluorescence, lightmicroscop,laser confocal scanning microscope and hair cells counting. Results The outer hair cells(OHC) and inner hair cells(IHC) of control group and methionine group were not damaged. The outer and inner hair cells of cisplatin group were damaged in various degree, and had remarkable difference compared with control group and methionine group(P ＜ 0. 05). The outer hair cells and inner hair cells of cisplatin + methionine group were damaged less than the cisplatin group with remarkable difference (tIHC = 3. 929, tOHC = 8. 582, P ＜0. 05). Conclusions Cisplatinum could damage the cochlear hair cells of the basal membrane in Kunming mice. Methionine might protect against cisplatin's damage on the cochlear hair cells.     

Supporting cells as a target of cisplatin-induced inner ear damage: therapeutic implications

OBJECTIVES/HYPOTHESIS: Cisplatin induces adverse effects such as ototoxicity and nephrotoxicity. Unexplained hearing improvement in sudden deafness and fluctuating hearing loss suggests the presence of some mechanisms other than the primary lesion of the outer hair cell. The authors' aim was to study the functional and morphological lesions induced in the cochlea of the rat after cisplatin injection. STUDY DESIGN: Prospective experimental morphological and functional study. METHODS: Forty-eight Wistar rats were given intraperitoneal injections of 5 mg/kg cisplatin. After short-, medium-, and long-term survival, animals were studied by means of auditory brainstem response testing and scanning electronic microscopy. RESULTS: An increased hearing loss was observed in animals with long-term survival compared with animals with short-term survival after a single dose of cisplatin. These findings correlated with a more intense injury of the supporting cells, continuing with the late deterioration of the hair cells. CONCLUSION: The study suggested that the initial damage of the supporting cells could be responsible for the late injury of the hair cells. This hypothesis was supported by the late increase in hearing loss after a single dose of cisplatin, emphasizing the role of the supporting cells in the cochlear changes induced by cisplatin.