NMDA Receptor Blockage Protects Against Permanent Noise-Induced Hearing Loss but Not Its Potentiation by Carbon Monoxide

Details

• Personal Author:
  Chen GD ; Fechter LD ; Kong J ; Reinhard K
• Description:
  While a clear role has been proposed for glutamate as a putative neurotransmitter at the inner hair cell type I spiral ganglion cell synapse, the possible role of excessive glutamate release in cochlear impairment and of NMDA receptors in such a process is uncertain. The present study compares the protective effects of (+)-MK-801, an NMDA receptor antagonist, and the relatively inactive isomer (-)-MK-801 against permanent noise-induced hearing loss (NIHL). The study also asks whether (+)-MK-801 can protect against the NIHL potentiation by carbon monoxide (CO). Rats (n = 6) were exposed to 100-dB, 13.6-kHz octave-band noise for 2 h after receiving injection of (+)-MK-801 hydrogen maleate (1 mg/kg), (-)-MK-801 hydrogen maleate (1 mg/kg), or saline. Other groups of animals were exposed to the combination of noise and CO (1200 ppm) after receiving (+)-MK-801 or saline. Additional subjects received (+)-MK-801, saline or CO exposure alone. Compound action potential (CAP) threshold sensitivities were compared 4 weeks after the exposures. The results show significant protection by (+)-MK-801 against the permanent CAP threshold elevation induced by noise alone, but no protective effect of (-)-MK-801. (+)-MK-801 produced limited protection against threshold shifts induced by the combination of noise and CO. Outer hair cell (OHC) loss was not protected by (+)-MK-801 administration. The data suggest that NMDA receptor stimulation may play a role in NIHL resulting from fairly mild noise exposure. The data do not support a role for NMDA receptor stimulation in the potentiation of NIHL that results from simultaneous exposure to CO and noise. [Description provided by NIOSH]
• Subjects:
  Animals Chemistry Hearing Hearing Loss Hearing Loss, Noise-Induced Laboratories Noise Noise, Occupational Occupational Health Safety Smokers Tobacco Products

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• Keywords:
  Animal Studies Chemical Analysis Cigarette Smoking Dose Response Exposure Assessment Hearing Disorders Hearing Protection Hearing Tests Laboratory Animals Noise Exposure Noise Frequencies Noise Induced Hearing Loss Noise Levels Ototoxicity Statistical Analysis Synergistic Effects

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• ISSN:
  0378-5955
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Oklahoma ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  108-115
• Volume:
  154
• Issue:
  1
• NIOSHTIC Number:
  nn:20029663
• Citation:
  Hear Res 2001 Apr; 154(1-2):108-115
• Contact Point Address:
  University of Oklahoma, Health Sciences Center, College of Pharmacy, Oklahoma City 73190
• Email:
  guangdi-chen@ouhsc.edu
• CAS Registry Number:
  Carbon monoxide (CAS RN 630-08-0)
• Federal Fiscal Year:
  2001
• NORA Priority Area:
  Disease and Injury: Hearing Loss
• Performing Organization:
  University of Oklahoma, Health Sciences Center, Oklahoma Center for Toxicology, Oklahoma City, Oklahoma
• Peer Reviewed:
  True
• Start Date:
  19970901
• Source Full Name:
  Hearing Research
• End Date:
  20000831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:a058e9e5c3a795a9b926c14270dc428d499d127c3e01290ff53a3a132d99cfa67253b496f963e4e43e02854c85a7da459d2b8e1332d9e448d9be670d58c44409
• Download URL:
  https://stacks.cdc.gov/view/cdc/190595/cdc_190595_DS1.pdf
• File Type:
  [PDF - 246.53 KB ]