Intra-cochlear administration of dexamethasone attenuates aminoglycoside ototoxicity in the guinea pig.
This study demonstrates the attenuation of aminoglycoside ototoxicity by cochlear infusion of dexamethasone (Dex) using a microcannulation-osmotic pump delivery system. The results indicate that treating the cochlea with Dex both before and after kanamycin administration was more effective in preventing ototoxicity than Dex treatment only after kanamycin administration. A concentration of 1 ng/ml Dex showed the greatest protective effect on both kanamycin-induced threshold shift of the auditory brainstem response and outer hair cell survival. These results show that the Dex treatment attenuates both functional and structural damage of the inner ear from aminoglycoside toxicity.
Department of Otolaryngology, Kansai Medical University, Fumizono-cho 10-15, Moriguchi, Osaka 570-8506, Japan. himenoc@takii.kmu.ac.jp
Chiemi
C
Himeno
Mototane
M
Komeda
Masahiko
M
Izumikawa
Keiji
K
Takemura
Masao
M
Yagi
Yang
Y
Weiping
Tadashi
T
Doi
Hiromichi
H
Kuriyama
Josef M
JM
Miller
Toshio
T
Yamashita
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D003051:Cochlea / Q000187:drug effects* / Q000293:injuries* / Q000473:pathology / Q000503:physiopathology; D003907:Dexamethasone / Q000008:administration & dosage*; D016503:Drug Delivery Systems; D004976:Ethacrynic Acid / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000633:toxicity; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D005938:Glucocorticoids / Q000008:administration & dosage; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects / Q000473:pathology; D007612:Kanamycin / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000633:toxicity*; D008297:Male
D000900:Anti-Bacterial Agents; D005938:Glucocorticoids; D007612:Kanamycin; D003907:Dexamethasone; D004976:Ethacrynic Acid