title: Reactive oxygen species in human inner ear perilymph.
abstract: CONCLUSIONS
  The results reported here provide the first evidence of the production of superoxide, a biologically relevant reactive oxygen species (ROS), in human inner ear perilymph (hIP) in pathological conditions, by the activity of the xanthine dehydrogenase/xanthine oxidase (XA/XO) enzyme system.
  
  
  OBJECTIVE
  To investigate the presence of ROS in hIP.
  
  
  METHODS
  Since damage and apoptosis of inner ear hair cells may occur as a result of ROS-mediated injury, we investigated the presence and production of ROS in 105 hIP samples; 98 collected from patients affected by profound sensorineural hearing loss, during surgery for cochlear implantation, and 7 controls, collected from patients affected by otosclerosis, in case of spontaneous leakage after stapedotomy. ROS production was investigated by spectrophotometric analysis and polyacrylamide gel electrophoresis (SDS-PAGE).
  
  
  RESULTS
  In hIP samples tested by cytochrome c reduction kinetics, the average superoxide production was 27.34 mumoles per mg of total protein, against 0.36 in controls. Some of these hIP samples, analyzed by cytochrome c reduction kinetics in the presence of xanthine, were found to be positive for ROS-producing XA/XO enzyme. These results were supported by SDS-PAGE analysis.
authors.affiliation: Department of Audiology, University Hospital of Ferrara, 44100 Ferrara, Italy. andrea.ciorba@unife.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Ciorba
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Gasparini
authors.forename: Milvia
authors.initials: M
authors.lastname: Chicca
authors.forename: Silvano
authors.initials: S
authors.lastname: Pinamonti
authors.forename: Alessandro
authors.initials: A
authors.lastname: Martini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003054:Cochlear Implants; D045304:Cytochromes c; D007758:Ear, Inner / Q000378:metabolism* / Q000473:pathology*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000378:metabolism; D010498:Perilymph / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013053:Spectrophotometry; D013201:Stapes Surgery; D014527:Uric Acid / Q000378:metabolism; D055815:Young Adult
chemical_list: D017382:Reactive Oxygen Species; D014527:Uric Acid; D045304:Cytochromes c