Neuroprotective effects of T-817MA against noise-induced hearing loss.
Oxidative stress, including reactive oxygen species and other free radicals, is thought to play an important role in neuronal cell death, including noise-induced hearing loss. 1-{3-[2-(1-Benzothiophen-5-yl)ethoxy]propyl}azetidin-3-ol maleate (T-817MA), a novel neurotrophic agent, protects against oxidative stress-induced neurotoxicity. This study examines the effects of T-817MA in noise-induced ototoxicity in the cochlea. Guinea pigs received treatment with T-817MA-enhanced water (0.2, 0.7 mg/ml) or untreated water (control) beginning 10 days prior to noise exposure and continuing through this study. All subjects were exposed to 4-kHz octave-band noise at 120-dB SPL for 5h. Auditory thresholds were assessed by sound-evoked auditory brainstem response at 4, 8, and 16kHz, prior to and 10 days following noise exposure. Hair cell damage was analyzed by quantitative histology. T-817MA significantly reduced threshold deficits and hair cell death. These results suggest T-817MA reduces noise-induced hearing loss and cochlear damage, suggesting functional and morphological protection.
Yamashita
Daisuke
D
Department of Otolaryngology, Keio University Hospital, 35 Shinanomachi, Shinjuku-Ku, Tokyo, Japan. daiy1013@aol.com
Shiotani
Akihiro
A
Kanzaki
Sho
S
Nakagawa
Masaya
M
Ogawa
Kaoru
K
D000818:Animals; D003051:Cochlea / Q000473:pathology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D006168:Guinea Pigs; D006198:Hair Cells, Auditory / Q000473:pathology; D006317:Hearing Loss, Noise-Induced / Q000517:prevention & control*; D008297:Male; D008298:Maleates / Q000494:pharmacology*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009622:Noise / Q000009:adverse effects; D018384:Oxidative Stress / Q000502:physiology; D013876:Thiophenes / Q000494:pharmacology*
C503102:1-(3-(2-(1-benzothiophen-5-yl) ethoxy) propyl)-3-azetidinol maleate; D008298:Maleates; D018696:Neuroprotective Agents; D013876:Thiophenes