title: The cochlea magnesium content is negatively correlated with hearing loss induced by impulse noise.
abstract: OBJECTIVE
  Magnesium is proved to attenuate acoustic trauma, and reactive oxygen species (ROS) formation is a critical role that involves hearing loss induced by impulse noise. We aimed to investigate the relationship between the cochlea magnesium content, ROS formation and hearing loss induced by impulse noise.
  
  
  METHODS
  Ninety pigmented guinea pigs were exposed to impulse noise. Auditory thresholds were assessed by sound-evoked auditory brainstem response (ABR) 24h before and 72h after exposure to impulse noise. 4-Hydroxynonenal(HNE) used as a marker of ROS was determined immunohistochemically. The cochlea magnesium content was examined with the method of energy dispersive x-ray analysis, and the cochlea was also detected with scanning electron microscope. The relationship between the cochlea magnesium content, ROS formation and hearing loss was analyzed.
  
  
  RESULTS
  There was loss of outer hair cell cilia accompanying with significant auditory threshold shift after impulse noise exposure. ROS was positive in the organ of Corti of all animals. The cochlea magnesium content was negatively correlated with ROS formation and hearing loss.
  
  
  CONCLUSIONS
  Inhibiting ROS formation is one of the mechanisms for magnesium to reduce acoustic trauma, and difference in cochlea magnesium contents is one of the factors that induce varying degrees of cochlear damage among each individual after acoustic trauma.
authors: Department of Otolaryngology, Guangzhou General Hospital of Guangzhou Military Command, Guangzhou, China. dr_xiong@163.com
authors: Min
authors: M
authors: Xiong
authors: Jian
authors: J
authors: Wang
authors: Chuanhong
authors: C
authors: Yang
authors: Huangwen
authors: H
authors: Lai
mesh_terms: D000818:Animals; D001309:Auditory Threshold; D003051:Cochlea / Q000737:chemistry* / Q000648:ultrastructure; D006168:Guinea Pigs; D006317:Hearing Loss, Noise-Induced / Q000378:metabolism*; D007150:Immunohistochemistry; D008274:Magnesium / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D009925:Organ of Corti / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D008274:Magnesium