摘要
目的观察L－甲状腺素对豚鼠庆大霉素耳毒性的预防作用，并对机制进行探讨。方法通过ABR测试、耳蜗铺片毛细胞计数、血液和外淋巴庆大霉素药代动力学分析等方法，对肌注庆大霉素（120mg·kg-1／·日-1）组、肌注相同剂量庆大霉素并同时口服L-甲状腺素（50u·kg－1·日-1）的合并用药组，以及相应对照组的豚鼠在用药一周和用药二周时的内耳形态、功能进行观察。结果用药二周后，合并用药组ABRⅣ波反应阈阈移明显小于肌注庆大霉素组（P＜0．05）。合并用药组外淋巴庆大霉素浓度也低于肌注庆大霉素组（P＜0．05）。说明L-甲状腺素确能桔抗庆大霉素在外淋巴中的积聚作用。但L－甲状腺素降低庆大霉素在外淋巴中的积聚作用可能并不是其拮抗耳毒性的唯一机制。结论L－甲状腺素确能预防庆大霉素的耳毒性，其机理有待于进一步探讨。
Objective To explore the mechanism of the prophylatic effect of L-thyroine on gentamycin ototoxicity in guninea pigs. Method We investigated the functional alterations and morphological changes in cochleas of guinea pigs by means of ABR threshold shifts of wave Ⅳ evoked by tone pipe stimuli, count of cochlear hair cells under optical microscopy, pharmacokinetics of gentamycin in serum and perilymph for 1 week or 2 weeks. Result The ABR threshold shifts of wave Ⅳof group TG2w were more lower than those of group GM2w(P<0.05). There was significant difference on gentamycin concentration in perilymph at 3h after GM injection between groups TG 2w and GM 2w (P<0.05). This implied that L-thyroxine could protect cochlear hair cells against gentamycin ototoxicity by means of decreasing gentamycin concentrations in perilymph. but the effect of reducing gentamycin concerntrations in perilymph was not the only explanation for the ettenuation of gentamycin ototoxicity by LAnthyroxine- Conclusion L-thyroxine could attenuate gentarricin ototoxicity. The mechanism needs to be further investigated.
出处
《中国中西医结合耳鼻咽喉科杂志》
2000年第4期164-167,共4页
Chinese Journal of Otorhinolaryngology in Integrative Medicine
