Effects of hydrogen peroxide on vestibular hair cells in the guinea pig: importance of cell membrane impairment preceding cell death.
CONCLUSIONS
Our findings indicate that oxidative stress induces morphological changes in vestibular hair cells and subsequently leads to cell death after 2.5 h.


OBJECTIVE
The aim of this study was to confirm the direct effects of oxidative stress on vestibular hair cells.


METHODS
Vestibular hair cells isolated from guinea pigs were loaded with 1 or 10 mM H2O2, and morphological changes were observed. In addition, in a viability/cytotoxicity assay system, the numbers of dead cells in isolated cristae ampullares were counted 1, 3, and 5 h after loading with H2O2 or artificial perilymph (control).


RESULTS
Reactive oxygen, in the form of H2O2, directly affects the cell membrane of isolated vestibular hair cells and causes swelling of the cell body, bleb formation, and shortening of the neck region. Morphological changes occur within 30 min after loading with H2O2, but a significant increase in the number of dead cells is noted only after 3 h.
Tanigawa
Tohru
T
Department of Otolaryngology, Aichi Medical University, Aichi, Japan. tanigawa@aichi-med-u.ac.jp
Tanaka
Hirokazu
H
Hayashi
Ken
K
Nakayama
Meiho
M
Iwasaki
Satoshi
S
Banno
Shinya
S
Takumida
Masaya
M
Brodie
Hirally
H
Inafuku
Shigeru
S
D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects* / Q000648:ultrastructure; D002478:Cells, Cultured; D006168:Guinea Pigs; D018069:Hair Cells, Vestibular / Q000187:drug effects* / Q000648:ultrastructure; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress
D016877:Oxidants; D006861:Hydrogen Peroxide