Protective effects of exogenous GM-1 ganglioside on acoustic injury of the mouse cochlea.
GM-1 ganglioside (GM-1), a glycosphingolipid, is embedded in the lipid layer of neuronal membranes and is one of the neuroprotective agents. To the best of our knowledge, the role of GM-1 has never been examined in hair cell injury. The purpose of this study was therefore to evaluate the effects of GM-1 on acoustic injury of the cochlea. Mice were exposed to 4-kHz pure tone of 128dB SPL (sound pressure level) for 4h. GM-1 was intraperitoneally administered immediately before the onset of acoustic overexposure. The threshold shift of the auditory brainstem response (ABR) and hair cell loss were then evaluated 2 weeks after acoustic overexposure. Immunostaining for 4-hydroxynonenal (4-HNE), indicative of lipid peroxidation, was also examined in animals subjected to acoustic overexposure. GM-1 treatment significantly decreased the ABR threshold shifts and hair cell loss after acoustic overexposure. And immunostaining for 4-HNE was reduced by GM-1 treatment. These findings suggest that GM-1 is involved in the protection of the cochlea against acoustic injury through inhibiting lipid peroxidation.
Tanaka
Shuho
S
Department of Otolaryngology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan.
Tabuchi
Keiji
K
Hoshino
Tomofumi
T
Murashita
Hidekazu
H
Tsuji
Shigeki
S
Hara
Akira
A
D000447:Aldehydes / Q000378:metabolism; D000818:Animals; D003051:Cochlea / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D005677:G(M1) Ganglioside / Q000494:pharmacology* / Q000502:physiology; D006199:Hair Cells, Auditory, Inner / Q000473:pathology; D015227:Lipid Peroxidation; D051379:Mice; D009622:Noise / Q000009:adverse effects*
D000447:Aldehydes; D005677:G(M1) Ganglioside; C027576:4-hydroxy-2-nonenal