Protective effect of edaravone in inner-ear barotrauma in guinea pigs.
OBJECTIVE
The purpose of this study was to determine the protective effect of edaravone, a free radical scavenger, on inner-ear barotrauma (IEB) in guinea pigs, based on a hypothesis implicating free radicals in the development of IEB.


METHODS
One hundred and twenty-five guinea pigs were divided into a control group and a pretreatment group. After auditory brainstem response (ABR) testing, the pretreatment group received 9.0 mg/kg intraperitoneal edaravone. Animals were exposed to pressure loading and then to further ABR testing.


RESULTS
The incidence of IEB was 62.7 per cent in the control group and 42.9 per cent in the pretreatment group (p<0.01). The distributions of threshold elevation in the control group were 37.3 per cent (for 10 dB or less), 21.3 per cent (for 20-30 dB), 18.0 per cent (for 40-60 dB) and 23.4 per cent (for 70 dB or more), and those in the pretreatment group were 57.1 per cent, 19.1 per cent, 14.3 per cent and 9.5 per cent, for the same respective decibel levels (p<0.01).


CONCLUSIONS
These results suggest that protective treatment with edaravone can significantly reduce both the incidence of IEB and the severity of the resultant ABR threshold elevation.
Masuda
Y
Y
Department of Otolaryngology, National Defense Medical College, Tokorozawa, Japan. flight.m@io.ocn.ne.jp
Tanabe
T
T
Murata
Y
Y
Kitahara
S
S
D000818:Animals; D000983:Antipyrine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D001309:Auditory Threshold / Q000502:physiology; D001469:Barotrauma / Q000517:prevention & control*; D007758:Ear, Inner / Q000293:injuries*; D000077553:Edaravone; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D016166:Free Radical Scavengers / Q000008:administration & dosage*; D006168:Guinea Pigs; D007274:Injections, Intraperitoneal; D011312:Pressure; D016896:Treatment Outcome
D016166:Free Radical Scavengers; D000077553:Edaravone; D000983:Antipyrine