Résumé
@#ObjectiveTo explore the effect of sodium selenite on gentamicin-induced ototoxicity.MethodsTwenty guinea pigs were randomly divided into the experimental group and control group with 10 animals in each group. The animals were treated with i.m injection of gentamicin (200 mg/kg/d for 8 consecutive days, and at same time, the experimental group was added with p.o tablet of sodium selenite (1 mg/kg/d). Before and after the administration, hearing function was evaluated by examination for auditory brain stem responses (ABR). The cochlear outer haircells were observed by scanning electronic microscope (SEM) and transmission electronic microscope (TEM).ResultsABR threshold of the control group was about 30 dB above that of the experimental group (P<0.01). The latency of waveⅠof the control group was about 0.23 ms above that of the experimental group (P<0.01). Under SEM, the cilia of the majority outer hair cells of the control group lodged even disappeared, while that of the experimental remained regular. Under TEM, in outer hair cells of the control group, mitochondrial crests were obscure, out-membrane was damaged and local protruding, the number of secondary lysosomes was increased, myeloid bodies appeared, but in the experimental group, outer hair cells basically remained normal.ConclusionSodium selenite has antitoxic effect on guinea pig cochlea injury induced by gentamicin in vivo.
Résumé
BACKGROUNDS AND OBJECTIVES: We developed a method of intraotic treatment using gentamicin (GM) in chinchillas. MATERIALS AND METHOD: An osmotic pump, connected near the round window by a Teflon tube (0.13mm ID X 0.18mm OD) through an opening in the scala tympani, continuously perfused 12microliter of GM per day for a week. In the three experimental groups (n=12), each animal was treated with a total dose of 0.1mg of GM for a week. Animals in the control group (n=4) were immediately sacrificed after perfusion with saline for a week. RESULTS: In the control group, there was no damage in any of the hair cells. In the treatment group, the hair cells were more severely damaged at 4 weeks than at 1 week. The outer hair cells were more sensitive to GM than the inner hair cells. Among the outer hair cells, the first rows were damaged first. The basal part of cochlea was damaged earlier than the apical. The ototoxic effect continued even after perfusion had ceased. CONCLUSIONS: This pump system limits drug distribution to the target tissue, minimizing systemic side effects while permitting precise control of delivery rate, volume, concentration and duration.