Effect of hydrogen peroxide on potassium currents in inner hair cells isolated from guinea pig cochlea.
Hydrogen peroxide (H₂O₂) is a ubiquitous reactive oxygen species that can induce several inner ear disorders. In this study, we recorded the potassium (K) currents in acutely isolated inner hair cells of guinea pig cochlea, and investigated the effects of H₂O₂. We also observed the morphological changes in inner hair cells induced by H₂O₂. In the H₂O₂ solutions, the amplitude of outward K currents (I(K,f) and I(K,s)) clearly decreased after perfusion for approximately 15 min. Despite the decrease in outward currents, small inward currents (I(K,n)) did not show any reduction. H₂O₂ induced morphological changes in the inner hair cells. All the inner hair cells in the H₂O₂ solutions showed shrinkage and granularity of the cell body and led to loss of viability. These results showed the vulnerability of inner hair cells to reactive oxygen species-induced inner ear disorders.
Kimitsuki
Takashi
T
Department of Otolaryngology, Graduate School of Medical Sciences, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Komune
Noritaka
N
Noda
Teppei
T
Takaiwa
Kazutaka
K
Ohashi
Mitsuru
M
Komune
Shizuo
S
D000818:Animals; D048430:Cell Shape / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D006168:Guinea Pigs; D006199:Hair Cells, Auditory, Inner / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D006309:Hearing / Q000187:drug effects / Q000502:physiology; D006311:Hearing Disorders / Q000503:physiopathology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D011188:Potassium / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects* / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism
D016877:Oxidants; D015221:Potassium Channels; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D011188:Potassium