Age-related hearing loss and expression of antioxidant enzymes in BDF1 mice.

Authors :: Tabuchi K
Hoshino T
Hirose Y
Hayashi K
Nishimura B
Nakayama M
Hara A
Source :: Acta oto-laryngologica [Acta Otolaryngol] 2011 Oct; Vol. 131 (10), pp. 1020-4. Date of Electronic Publication: 2011 Jun 01.
Publication Year :: 2011
Abstract: Conclusion: Our data suggest that the changes in expression of antioxidant enzymes may cause age-related hearing loss (AHL).<br />Objectives: AHL is an aging process of the inner ear, and oxidant stressors are considered to be one of the leading causes. We investigated the hearing level and expression profile of antioxidant enzymes in aged mice.<br />Methods: Mice aged 3, 6, and 11 months were used. Hearing levels of the mice were examined using the auditory brainstem response (ABR). After measuring the ABR threshold, cochleae were dissected. RNA was isolated from the cochleae, and cDNA was synthesized using the retro-transcription enzyme. Expression of the antioxidant enzymes was measured by quantitative real-time PCR.<br />Results: The ABR thresholds of the BDF1 mice were elevated by 6 months of age. The expression of superoxide dismutase 1 (SOD1) and heme oxygenase 1 (HO1) at 11 months of age significantly decreased compared with that of those at 6 months of age. In contrast, a decrease in the expression level was not observed regarding NAD(P)H-quinone oxidoreductase 1 (NQO1).