Prednisolone prevents transient ischemia-induced cochlear damage in gerbils.
CONCLUSIONS
Prednisolone protects against inner ear damage, even when administered after ischemic injury in Mongolian gerbils.


OBJECTIVE
The effect of prednisolone on ischemia-induced cochlear damage was investigated in Mongolian gerbils.


METHODS
The bilateral vertebral arteries were occluded for 15 min to transiently induce cochlear ischemia, followed by an intraperitoneal injection of prednisolone (1 mg/kg) or physiological saline (control). Sequential changes in hearing were evaluated by recording the auditory brainstem response (ABR) before and at 1, 4, and 7 days after treatment. In our histologic analysis, the numbers of dead and intact inner hair cells (IHCs) were counted in specimens stained with rhodamine-phalloidin.


RESULTS
In control animals, transient ischemia increased the ABR threshold (24.2 +/- 8.6 dB) within 7 days of treatment, whereas prednisolone-treated animals exhibited a threshold of 14.2 +/- 9.2 dB. Furthermore, the percent IHC loss at the basal turn of the cochlea was 26.5 +/- 11.4% in control animals compared with 5.3 +/- 3.0% in the prednisolone-treated group.
Department of Otolaryngology, Ehime University School of Medicine, Ehime, Japan. t-maetani@kitano-hp.or.jp
Toshiki
T
Maetani
Jun
J
Hyodo
Shoichiro
S
Takeda
Nobuhiro
N
Hakuba
Gyo
G
Kiyofumi
D000818:Animals; D003051:Cochlea / Q000098:blood supply*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D005849:Gerbillinae; D005938:Glucocorticoids / Q000494:pharmacology*; D006199:Hair Cells, Auditory, Inner / Q000166:cytology / Q000187:drug effects; D007274:Injections, Intraperitoneal; D007511:Ischemia / Q000517:prevention & control*; D008297:Male; D011239:Prednisolone / Q000494:pharmacology*
D005938:Glucocorticoids; D011239:Prednisolone