中文摘要：

目的验证阳离子脂质体介导脑红蛋白（neuroglobin，NGB）基因转染对庆大霉素致豚鼠耳毒性的保护作用。方法将ABR反应阈均不超过40dBSPL的120只健康花色豚鼠随机分为5组，每组24只：I组：空白对照组；II组：人工外淋巴液对照组（经左耳注入人工外淋巴液）；III组：人工外淋巴液实验组（经左耳注入人工外淋巴液后肌肉注射庆大霉素）；IV组：空质粒转染组（经左耳注入空质粒pEGFP—C1后肌肉注射庆大霉素）；V组：NGB基因转染组（经左耳注入pEGFP—NGB后肌肉注射庆大霉素），庆大霉素均经后腿肌肉注射120mg·kg^-1·d^-1，共给药14天。停止给药后喂养14天，各组均行ABR检测，耳蜗基底膜铺片、免疫组化观察各组豚鼠耳蜗基底膜毛细胞形态学及NGB蛋白表达的变化。结果给药后I组ABR反应阈平均为37．22dBSPL（左耳）和36．94dBSPL（右耳），II组阈值平均为37．22dBSPL（左耳）和37．50dBSPL（右耳），III组阈值平均为119．44dBSPL（左耳）和122．22dBSPL（右耳）；IV组阈值平均为119．72dBSPL（左耳）和120．83dBSPL（右耳）；V组阈值平均为83．89dBSPL（左耳）和100．56dBSPL（右耳）。V组ABR反应阈较I组和Ⅱ组显著升高（P〈0．05），较Ⅲ组和Ⅳ组显著降低（P〈0．05）。V组中手术耳ABR反应阈较非手术耳降低（P〈0．05）。耳蜗基底膜铺片示I组和Ⅱ组内外毛细胞排列整齐，无缺失，Ⅲ组和Ⅳ组内外毛细胞极少量残存，其中ABR阈值大于135dBSPL的豚鼠耳蜗毛细胞几乎消失殆尽，V组毛细胞部分缺失，且主要是外毛细胞；免疫组织化学染色示V组耳蜗毛细胞NGB蛋白表达量较其余各组均显著增高（P〈0．05），其余各组几乎均未见明显阳性表达。结论本研究成功验证了阳离子脂质体介导NGB基因转染对庆大霉素致豚鼠耳毒性具有有效的保护作用。

英文摘要：

Objective To study the protective effects of cationic liposome--mediated NGB gene transfected into deaf guinea pig cochlea induced by gentamicin. Methods 120 healthy guinea pigs（ABR threshod ≤40 dB SPL） were employed in this experiment and divided randomly into five groups（24 each group）：group Ⅰ ： blank control group ; group Ⅱ ： artificial perilymph control group （artificial perilymph was injected into left ear ）; group Ⅲ ： arti- ficial perilymph experimental group （artificial perilymph was injected into left ear and then gentamicin administra- tion） ; group IV： empty plasmid transfection group （empty plasmid pEGFP-C1 was injected into left ear and then gentamicin administration）; group V： NGB gene transfection group （pEGFP--NGB was injected into left ear and then gentamicin administration）. Gentamicin was injected with 120 mg kg-1 d-1 for 14 days , then observed the animals for 14 days. Auditory brainstem response （ABR）, stretched preparation technique, immunohistochemistry were uti- lized to evaluate the auditory function, the morphological changes of the hair cells on basement membrane in cochlear and the expression of NGB protein of each group. Results Average ABR thresholds in all the groups： group I ： 37.22 dB SPL（left ear） and 36.94 dB SPL（right ear） ; group IT ： 37.22 dB SPL（left ear） and 37.50 dB SPL（right ear） ; group III .119.44 dB SPL（left ear） and 122.22 dB SPL（right ear） ; group IV： 119.72 dB SPL（left ear） and 120.83dB SPL（right ear） ;group V= 83.89dB SPL（left ear） and 100.56 dB SPL （right ear）. The stretching of cochlear basement membrane showed that both the inside and outside hair cells in group I and group II arranged neatly and had no defects. In group III and group IV, the hair cells almost vanished corresponding with the ABR threshold （more than 135 dB SPL）. Some hair cells in group V were missing ,damaged lightly, and mainly on the outer hair cells;Immunohistochemistry showed that NGB protein