Succinate Dehydrogenase (SDH) Activity in Hair Cells: A Correlate for Permanent Threshold Elevations

Details

• Personal Author:
  Chen GD ; Fechter LD ; McWilliams ML
• Description:
  Hair cell loss is often used as a histological correlate of hearing loss. However, the histological and the physiological data are not always well correlated. This paper investigates the use of succinate dehydrogenase (SDH) activity in the hair cells as a marker of cellular dysfunction and so the loss of auditory sensitivity. In our previous studies, potentiation of noise-induced auditory threshold elevation by carbon monoxide (CO) was observed [Chen and Fechter, 1999; Chen et al., 1999]. However, its histological basis is still unclear. In this study, rats were exposed to 100-dB octave-band noise (center frequency=13.6 kHz, 2 h) or to the combination of the noise and CO (1200 ppm). Threshold elevation of compound action potential (CAP) and cochlear histological changes were assessed 4 weeks after exposure. The noise alone caused CAP threshold elevations with little if any or without hair cell loss. However, the SDH activity in the hair cells decreased after the exposure. The SDH reduction, especially in the inner hair cells, was well related to the loss of auditory sensitivity. The combined exposure to noise and CO caused more severe CAP threshold elevation and SDH activity reduction than did the noise alone and it also caused significant outer hair cell loss. However, across all the test frequencies, neither the hair cell loss nor the SDH reduction alone had good correlation to the reduction of the auditory sensitivity. Under this situation, CAP threshold elevation seemed to follow OHC loss at high frequencies and to follow SDH reductions in the IHCs at low frequencies, where no hair cell loss occurred. [Description provided by NIOSH]
• Subjects:
  Hearing Hearing Loss Hearing Loss, Noise-Induced Noise Noise, Occupational Occupational Health Safety Solvents
• Keywords:
  Cell Metabolism Cellular Structures Hearing Impairment Hearing Level Hearing Loss Hearing Protection Hearing Tests Hearing Threshold Noise Induced Hearing Loss Organic Solvents Ototoxicity 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:
  91-100
• Volume:
  145
• Issue:
  1
• NIOSHTIC Number:
  nn:20029810
• Citation:
  Hear Res 2000 Jul; 145(1-2):91-100
• Contact Point Address:
  University of Oklahoma, Health Sciences Center, College of Pharmacy, P.O. Box 26901, 1110 N. Stonewall, Oklahoma City, OK 73190
• Email:
  guangdi-chen@ouhsc.edu
• CAS Registry Number:
  Carbon monoxide (CAS RN 630-08-0) ; Cyanide (CAS RN 57-12-5)
• Federal Fiscal Year:
  2000
• 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:f97b4a2dd96bdb8a2bb3ce33d4adce9d7f1f4f1fa80b125e0b63f527ccb31a296df1d69a6f87eef73124e08958e55cb660d97d9d7992393f42c2b6b2c7dfcc53
• Download URL:
  https://stacks.cdc.gov/view/cdc/190718/cdc_190718_DS1.pdf
• File Type:
  [PDF - 470.52 KB ]