Protective effect of edaravone against endolymphatic hydrops.
CONCLUSIONS
Our findings suggest that edaravone prevented the production of reactive oxygen species (ROS). Edaravone also delayed the formation of endolymphatic hydrops in guinea pigs, but had no effect on endolymphatic hydrops.


OBJECTIVE
To analyse the protective effect of a free radical scavenger, edaravone, on endolymphatic hydrops.


METHODS
Guinea pigs were subjected to surgical obliteration of the endolymphatic duct (ED). For the detection of ROS, group 1 received intraperitoneal injections of edaravone (3 mg/kg/day) for 2 days, group 2 received edaravone for 2 weeks, group 3 saline for 2 days, and group 4 saline for 2 weeks. ROS production by the organ of Corti and stria vascularis was examined by using dihydrotetramethylrosamine. For the morphological analysis, guinea pigs were divided into five groups, i.e. 2 or 4 weeks after ED obliteration, 2 weeks with edaravone, first or last 2 weeks with edaravone and sacrificed 4 weeks after ED obliteration. Increases in the ratios of the cross-sectional area of scala media were analysed quantitatively to assess the degree of endolymphatic hydrops among the above-mentioned five groups of the hydropic cochlea.


RESULTS
ROS was detected both in the organ of Corti and in the lateral wall of cochleae 2 days after ED obliteration. Edaravone prevented the production of ROS and also attenuated the formation of endolymphatic hydrops in the acute hydrops group.
Takumida
Masaya
M
Department of Otolaryngology, Hiroshima University Faculty of Medicine, 1-2-3 Kasumicho, Minamiku, Hiroshima 734-8551, Japan. masati@hiroshima-u.ac.jp
Takeda
Taizo
T
Takeda
Setsuko
S
Kakigi
Akinori
A
Nakatani
Hiroaki
H
Anniko
Matti
M
D000818:Animals; D000983:Antipyrine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D000077553:Edaravone; D018159:Endolymphatic Hydrops / Q000175:diagnosis / Q000378:metabolism / Q000517:prevention & control*; D005260:Female; D005500:Follow-Up Studies; D016166:Free Radical Scavengers / Q000008:administration & dosage*; D006168:Guinea Pigs; D007274:Injections, Intraperitoneal; D008856:Microscopy, Fluorescence; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D016896:Treatment Outcome
D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D000077553:Edaravone; D000983:Antipyrine