氨基甙类药物对内淋巴积水豚鼠前庭及耳蜗功能的影响

Effect of Aminoglycoside on Vestibular and Cochlear Functions in Guinea Pigs with Endolymphatic Hydrops

目的 探讨氨基甙类药物对内淋巴积水豚鼠前庭及耳蜗功能的影响。方法８只内淋巴积水模型豚鼠全身应用链霉素，观察给药前后豚鼠行为学、眼震电图（ＥＮＧ），听性脑干反应（ＡＢＲ），畸变产物耳声发射（ＤＰＯＡＥ）及形态学变化。结果 给药后未出现头偏斜、走路不稳等前庭功能紊乱的行为征象，连续给药第１０天、停药后第７天摆动幅度９０°，停药后第２１天，摆动幅度为９０°、１２０°时积水侧眼震反应降低的幅度明显大于对照耳（Ｐ＜０．０５）。停药后第７天，积水耳给药前后ＡＢＲ阈值升高的幅度同对照耳相比差异有显著性意义（Ｐ＜０．０５），积水耳升高的幅度大，其余各测试点差异无显著性意义。结论 本研究结果表明积水耳的前庭及耳蜗对氨基甙类药物的敏感性较正常耳高，但本研究的给药方案对耳蜗功能无显著性影响。

Objective To investigate the effect of aminoglycosides on vestibular and cochlear functions in guinea pigs with endolymphatic hydrops(ELH). Methods Streptomycin sulfate was injected subcutaneously into eight guinea pigs with ELH. General behaviour was observed after injection. Electronystagmography(ENG), auditory brainstem responses (ABRs) and distortion product otoacoustic emissions ( DPOAEs) were recorded before injection and repeated for up to 31 days. Results No signs of vestibular disturbance were observed after application of streptomycin. Reduction of nystagmic responses on hydropic ears was found more significant compared with the canted ears on the 10th day of injection( Pendular amplitude: 90°) and an the 7th day (90°) ,21th day(90°, 120°) after the termination of drug administration respectively. The amplitudes of ABRs thresholds elevation on the hydropic ears were statistically significant compared with the contralateral ears on the 7th day after ending drug administration(P < 0.05). No difference was found on the other day. Histologic examination revealed reduction of the degree of ELH in the cochlea and sensory cells in three respective canal cristae. Conclusion The study showed that the vestibule and cochlea in hydropic ears were more vulnerable to aminoglycosides. However, our schedule of drug administration showed that there was no significant influence on the function of cochlea.