Glial cell line-derived neurotrophic factor has a dose dependent influenceon noise-induced hearing loss in the guinea pig cochlea

Citation
F. Shoji et al., Glial cell line-derived neurotrophic factor has a dose dependent influenceon noise-induced hearing loss in the guinea pig cochlea, HEARING RES, 142(1-2), 2000, pp. 41-55
Citations number
76
Categorie Soggetti
da verificare
Journal title
HEARING RESEARCH
ISSN journal
03785955 → ACNP
Volume
142
Issue
1-2
Year of publication
2000
Pages
41 - 55
Database
ISI
SICI code
0378-5955(200004)142:1-2<41:GCLNFH>2.0.ZU;2-H
Abstract
We examined the effectiveness of glial cell line-derived neurotrophic facto r (GDNF) to attenuate cochlear damage from intense noise stress. Subjects w ere exposed to 115 dB SPL one octave band noise centered at 4 kHz for 5 h. They received artificial perilymph with or without GDNF into the left scala tympani at 0.5 mu l/h from 4 days before noise exposure through 8 days fol lowing noise exposure. Different concentrations of GDNF (1 ng/ml, 10 ng/ml, 100 ng/ml, and 1 ng/ml) were applied chronically directly into the guinea pig cochlea via a microcannula and osmotic pump.:Noise-induced hearing loss was assessed with pure tone auditory brainstem responses (at 2, 4, 8 and 2 0 kHz), measured, prior to surgery, 1 day before noise exposure, and 7 days following noise exposure. Subjects were killed on day 8 following exposure for histological preparation and quantitative assessment of hair cell (HC) damage. A dose-dependent protective effect of GDNF on both sensory cell pr eservation and hearing function was found in the treated ears. At 1 ng/ml, GDNF showed no significant protection; at 10 ng/ml, GDNF showed significant HC protection; and at 100ng/ml, it was greater and bilateral. At 1 mu g/ml , GDNF appeared to have a toxic effect under noise stress in some cochleae. These findings indicate that GDNF at certain concentrations can effectivel y protect the inner ear from noise-induced hearing loss. (C) 2000 Elsevier Science B.V. All rights reserved.