Involvement of oxidative stress in potentiation of noise induced hearing loss (NIHL) by chemical contaminants.
Fechter LD; Pouyatos B; Gearhart CA
Toxicologist 2005 Mar; 84(Suppl 1):10
Permissible workplace exposure limits for noise and for chemical contaminants generally rely upon laboratory and epidemiological investigations that entail exposure to the single agent of interest. However, a growing body of research shows that a variety of chemical contaminants, including those that have no effect upon auditory function, can potentiate noise induced hearing loss. Such potentiation is particularly noteworthy when it occurs for low intensity noise exposures that approach the permissible human noise exposure standards.We predict that chemicals able to impair intrinsic antioxidant mechanisms potentiate NIHL since reactive oxygen species may be generated even at low noise levels. Combined exposure of rats to hydrogen cyanide and mild noise yields significant auditory impairment while at neither agent given alone resulted in hearing loss. Using antioxidant drug treatments to protect auditory function and pro-oxidant drugs to promote oxidative stress we find support for our hypothesis that oxidative stress does play a role in potentiation of noise induced hearing loss by hydrogen cyanide.
Noise induced hearing loss; Chemical reactions; Ototoxicity; Hearing loss; Noise exposure; Free radical generation; Free radicals; Tissue disorders; Synergism
Disease and Injury: Hearing Loss
The Toxicologist. Society of Toxicology 44th Annual Meeting and ToxExpo, March 6-10, 2005, New Orleans, Louisiana
University of Oklahoma, Health Sciences Center, Oklahoma Center for Toxicology, Oklahoma City, Oklahoma