Yin Jinshu, Zhai Suoqiang, Guo Wei, Hu Yinyan, Shi Li
Department of Otorhinolaryngology, Railway General Hospital, Beijing 100038, China.
Zhonghua Yi Xue Za Zhi. 2002 Sep 10;82(17):1192-4.
To observe the expression of cationic stearylamine (SA) liposome mediated basic fibroblast growth factor/green fluorescence protein (bFGF/GFP) gene in the cochlea of guinea pig, and evaluate the protection and rescue action of bFGF against the damage caused by gentamicin.
Thirty-six guinea pigs were divided into 3 experimental groups. Prevention group with inoculation of SA-bFGF/GFP complexes through the round window of right ear and injection of gentamicin 150 mg.kg(-1).d(-1) one day after for 8 days and rescue group with injection of gentamicin for 8 days and infusion of SA-bFGF/GFP complexes in the same way on the ninth day, and control group with only injection of gentamicin for 8 days. Auditory brainstem responses (ABR) was measured prior to and after the administration and before the animals were killed respectively. The animals were killed after the experiment and ABR test, and specimens and slices of chochleae were made to examine the absence of outer and inner hair cells. The expression of GFP in cochlea shown by green fluorescence was observed with fluorescent microscopy.
Fluorescent microscopy showed green fluorescence in the cochleae of guinea pigs in prevention and rescue groups. There was no significant difference in ABR threshold between the left and right ears of animals in each group before and after experiment, among both ears of animals in the 3 groups before experiment, and between prevention and rescue group groups before killing (all P > 0.05). However, the ABR thresholds in prevention group and rescue group were significantly lower than that in control group before the animals were killed (P < 0.01 and P < 0.05). The average number of lost outer hair cells was 5 106 +/- 299 cells and 5 605 +/- 109 cells in prevention group and rescue group respectively, without a significant difference between them (P > 0.05). The average amount of missing inner hair cells was 301 +/- 64 cells and 487 +/- 92 cells in prevention group and rescue group respectively, without a significant difference between them (P > 0.05), and significantly lower than that in control group (1 062 +/- 67, P < 0.01 and P < 0.05). The average amount of missing outer hair cells in control group was 6 248 +/- 119 cells, significantly higher than that in prevention group (5 106 +/- 299, P < 0.01) and that in rescue group (5 605 +/- 109, P < 0.05).
SA-liposome mediated bFGF/GFP gene, which was perfused in one ear, can be expressed highly in both cochleae of the guinea pig, and may protect and rescue cochlea against gentamicin ototoxicity.
观察阳离子硬脂胺（SA）脂质体介导的碱性成纤维细胞生长因子/绿色荧光蛋白（bFGF/GFP）基因在豚鼠耳蜗中的表达，评价bFGF对庆大霉素所致损伤的保护和挽救作用。
36只豚鼠分为3个实验组。预防组经右耳圆窗接种SA-bFGF/GFP复合物，1天后注射庆大霉素150mg·kg⁻¹·d⁻¹，共8天；挽救组注射庆大霉素8天，第9天以同样方式输注SA-bFGF/GFP复合物；对照组仅注射庆大霉素8天。分别在给药前、给药后及处死动物前测量听性脑干反应（ABR）。实验及ABR测试后处死动物，制作耳蜗标本和切片，检查外毛细胞和内毛细胞缺失情况。用荧光显微镜观察耳蜗中绿色荧光显示的GFP表达。
荧光显微镜下观察到预防组和挽救组豚鼠耳蜗中有绿色荧光。每组动物实验前后双耳ABR阈值、3组动物实验前双耳ABR阈值及处死前预防组与挽救组之间比较，差异均无统计学意义（均P>0.05）。但处死动物前，预防组和挽救组的ABR阈值均显著低于对照组（P<0.01和P<0.05）。预防组和挽救组外毛细胞平均丢失数分别为5106±299个和5605±109个，两者差异无统计学意义（P>0.05）。预防组和挽救组内毛细胞平均缺失数分别为301±64个和487±92个，两者差异无统计学意义（P>0.05），且均显著低于对照组（1062±67，P<0.01和P<0.05）。对照组外毛细胞平均缺失数为6248±119个，显著高于预防组（5106±299，P<0.01）和挽救组（5605±109，P<0.05）。
SA-脂质体介导的bFGF/GFP基因经单耳灌注后，可在豚鼠双耳耳蜗中高表达，可能对庆大霉素耳毒性具有保护和挽救耳蜗的作用。
