A comparison of three evaluation methods for ototoxicity after ethyl benzene exposure
Level: Advanced
Numbers of Slides: 20
Abstract:
Rats were exposed to the organic solvent ethyl benzene at 0, 300, 400 and 550 ppm in air for 8 hours/day for 5 consecutive days. Three to six weeks after the exposure, auditory function was tested by measuring distortion product otoacoustic emissions (DPOAEs) and compound action potentials (CAPs). In addition, outer hair cell (OHC) loss was quantified by histological examination. Generally, the frequency region found to be affected after ethyl benzene exposure was similar with all three evaluation methods. However, at 400 ppm ethyl benzene, CAP threshold shifts were statistically significant and in line with OHC loss, but DPOAE measurements merely showed a trend for loss. Thus, DPOAEs seem to be less sensitive than CAP and OHC counts.