Abstract: 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.

Key words: sodium selenite, gentamicin, ototoxicity, scanning electron microscopy, transmission electron microscopy