RESUMO
Objective To investigate the effects of hydrogen peroxide on function and morphology of guinea pig cochlea in vivo.Methods Animals were divided into four groups and their cochleas were perfused with artificial perilymph(AP), 50 ?M H 2O 2, 100 ?M H 2O 2 and 200 ?M H 2O 2 resolved in AP separately. The compound action potential(AP) and cochlear microphonic(CM) were recorded after two-hours' perfusion. Then hydrogen peroxide-induced cell damage in the inner ear was investigated with morphologic method.Results In all H 2O 2 groups, CAP threshold shifts and CM amplitude shifts were significantly greater than that of APL group. The effect of H 2O 2 perfusion on cochlear function showed dose-dependence. OHCs were major targets of H 2O 2-induced cell death, while Hensen's cells did not show any signs of damage in the presence of H 2O 2. Conclusion Hydrogen peroxide, as an ubiquitous reactive oxygen species(ROS), can induce cochlea dysfunction and damage of cells in guinea pig inner ear. Hensen's cells maybe more resistant to the damage of ROS than hair cells.