Repository hosted by TU Delft Library

Home · Contact · About · Disclaimer ·
 

Ethyl benzene-induced ototoxicity in rats : a dose-dependent mild-frequency hearing loss

Publication files not online:

Author: Cappaert, N.L.M. · Klis, S.F.L. · Baretta, A.B. · Muijser, H. · Smoorenburg, G.F.
Type:article
Date:2000
Institution: Centraal Instituut voor Voedingsonderzoek TNO
Source:JARO Journal of the Association for Research in Otolaryngology, 4, 1, 292-299
Identifier: 41920
Keywords: Integrated optics · Deposition · Insulators · Electrocochleography · Ethyl benzene · Otoacoustic emissions · Ototoxicity · Outer hair cells · Rats · Ethylbenzene · Action potential · Animal experiment · Animal model · Auditory stimulation · Auditory system function · Basilar membrane · Controlled study · Distortion product otoacoustic emission · Dose calculation · Electrocochleography · Hair cell · Hearing loss · Nonhuman · Ototoxicity · Priority journal · Rat · Stimulus response · Action Potentials · Animals · Benzene Derivatives · Cell Count · Deafness · Dose-Response Relationship, Drug · Hair Cells, Outer · Otoacoustic Emissions, Spontaneous · Perceptual Distortion · Rats

Abstract

Rats were exposed to ethyl benzene at 0, 300, 400 and 550 ppm for 8 hours/day for 5 consecutive days. Three to six weeks after the exposure, auditory function was tested by measuring compound action potentials (CAP) in the frequency range of 1-24 kHz and 2f1-f2 distortion product otoacoustic emissions (DPOAEs) in the frequency range of 4-22.6 kHz. In addition, outer hair cell (OHC) loss was quantified by histological examination. The lowest concentration ethyl benzene had no effect on any of the above measures. At 400 ppm, auditory thresholds were increased by 15 and 16 dB at 12 and 16 kHz, respectively, and at 550 ppm by 24, 31, and 22 dB at 8, 12, and 16 kHz, respectively. DPOAE amplitude growth with stimulus level was affected only after 550 ppm at 5.6, 8, and 11.3 kHz. OHC loss was found in two of the five examined locations in the cochlea. At 400 ppm, 25% OHC loss was found at the 11- and 21-kHz region. The highest concentration evoked 40% and 75% OHC loss at the 11- and 21-kHz location, respectively. Thus, the mid-frequency region of rats is affected after exposure to relatively low concentrations of ethyl benzene (400-550 ppm). These results indicate that ethyl benzene is one of the most potent ototoxic organic solvents known today. Chemicals/CAS: Benzene Derivatives; ethylbenzene, 100-41-4