Protective effects of glucocorticoids on ischemia-reperfusion injury of outer hair cells.
OBJECTIVE
This animal study aimed to investigate effects of glucocorticoids on the functional recovery of outer hair cells (OHCs) after transient ischemia.


METHODS
Distortion-product otoacoustic emission (DPOAE) was examined before, during, and after transient cochlear ischemia of 30 minutes using albino guinea pigs.


RESULTS
DPOAE decreased to noise level during ischemia. On recirculation, DPOAE initially recovered with time until 20 minutes after the onset of reperfusion, but thereafter, the DPOAE level gradually decreased toward the noise level in the control animals. Prednisolone and methylprednisolone significantly improved the DPOAE level 60 minutes after the onset of reperfusion.


CONCLUSIONS
The present findings suggest that glucocorticoids possess protective effects against ischemia-reperfusion injury of OHCs.
Department of Otolaryngology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan. ktabuchi@md.tsukuba.ac.jp
Keiji
K
Tabuchi
Keiko
K
Oikawa
Hidekazu
H
Murashita
Tomofumi
T
Hoshino
Shigeki
S
Tsuji
Akira
A
Hara
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D003051:Cochlea / Q000098:blood supply; D004195:Disease Models, Animal; D005938:Glucocorticoids / Q000627:therapeutic use*; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000098:blood supply*; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects; D011239:Prednisolone / Q000627:therapeutic use; D015427:Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D016896:Treatment Outcome
D005938:Glucocorticoids; D011239:Prednisolone