Effect Of Trace Element Se On Noise-induced Hearing Loss In Guinea Pigs

Objective: To explore the protective effect of trace element Se on noise-induced hearing loss in guinea pigs.Methods: 40 male pigmented guinea pigs were randomly divided into 4 groups( normal control group, Se group, Saline+ noise and Se+ noise group, 10 animals each group). Normal control group was not any treated, Se group was treated only with Na2SeO3, Na2SeO3 was administered for consecutive 5 days(0.7mg/kg,i.p.),Saline+ noise group was given the same dose of saline (i.p.) for consecutive 5 days before noise exposure, Se+ noise group was received the same dose of Na2SeO3 (i.p.) for consecutive 5 days, once a day. The condition of noise is octave band noise with a central frequency of 4kHz, 120dB SPL for 4h. All animals received ABR threshold recording before noise exposure. 1 day after noise exposure, 5 animals of each group were decapitated immediately, then their cochleae were removed and tested the activity of GSH-Px. The remnant 5 animals of each group were measured with ABR threshold 10 day after noise exposure. After the latest test of ABR, animals were killed and their basement membranes were stretched and stained.Results: the ABR threshold of Saline+ noise group and Se+ noise group were increased 1 day and 10 day after noise exposure as compared with those before noise exposure, the difference between them were significant statistically. The ABR threshold shift of Saline+ noise group between before and after noise exposure was higher than that of Se+ noise group, the difference between them were significant statistically. The activity of GSH-Px Se group was higher than that of normal control group and the activity of GSH-Px of normal control group was higher than that of Saline+ noise, the difference between them were significant statistically. Laser scanning confocal microscopy showed that the outer hair cells displayed apoptosis, necrosis and missing in Saline+ noise group and Se+ noise group. The ratio of damaged cell of Saline+ noise group was significantly higher than that of Se+ noise group.Conclusion: Se can increase the activity of GSH-Px in cochlea tissue and then protect against noise-induced hearing loss to some extent because GSH-Px as a antioxidant maybe neutralize some noise-induced OFR/ROS.