Low-level laser therapy for prevention of noise-induced hearing loss in rats.
Neurosci Lett
; 595: 81-6, 2015 May 19.
Article
in En
| MEDLINE
| ID: mdl-25797186
ABSTRACT
Noninvasive low-level laser therapy (LLLT) is neuroprotective, but the mechanism of this effect is not fully understood. In this study, the use of LLLT as a novel treatment for noise-induced hearing loss (NIHL) is investigated. Sprague-Dawley rats were exposed to intense noise and their right ears were irradiated with an 808nm diode laser at an output power density of 110 or 165mW/cm(2) for a 30min period for 5 consecutive days. Measurement of the auditory brainstem response revealed an accelerated recovery of auditory function in the groups treated with LLLT compared with the non-treatment group at days 2, 4, 7 and 14 after noise exposure. Morphological observations also revealed a significantly higher outer hair cell survival rate in the LLLT groups. Immunohistochemical analyses for inducible nitric oxide synthase (iNOS) and cleaved caspase-3 were used to examine oxidative stress and apoptosis. Strong immunoreactivities were observed in the inner ear tissues of the non-treatment group, whereas these signals were decreased in the LLLT group at 165mW/cm(2) power density. Our findings suggest that LLLT has cytoprotective effects against NIHL via the inhibition of iNOS expression and apoptosis.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Low-Level Light Therapy
/
Hearing Loss
/
Noise
Type of study:
Etiology_studies
Limits:
Animals
Language:
En
Journal:
Neurosci Lett
Year:
2015
Document type:
Article
Affiliation country:
Japón