title: Efficacy of the cat deafening method: Co-administration of ethacrynic acid and kanamycin.
abstract: OBJECTIVE
  This study was designed to determine if hearing status monitoring during intravenous infusion of EA reduces individual variability and to evaluate the correlation between EA dose and Bwt.
  
  
  METHODS
  Twenty-five cats with the mean age of 24 ± 3.7 weeks (range = 20.6-28.3) and a mean weight of 3.21 ± 0.84 kg (range = 1.9-5.1) were administered a subcutaneous injection of KM (300 mg/kg) followed by an intravenous infusion of EA (1 mg/min). Click-evoked auditory brainstem responses (ABRs) were recorded to monitor hearing during the infusion. When ABR thresholds exceeded a 90 dB sound pressure level, the infusion of EA was terminated. Histopathology forapex, middle, and base sections of the cochlea were examined after 6 months.
  
  
  RESULTS
  The dose of EA was optimized for deafening through simultaneous ABR measurements. Bwt was positively correlated with EA dose (mg) (p < 0.001, R(2) = 0.548), which was different from a study previously reported. Cochlear histopathology assessments revealed an absence of organ of Corti in the majority of cochleae.
  
  
  CONCLUSIONS
  Co-administration of kanamycin (KM) and ethacrynic acid (EA) was an easy and effective method for deafening procedures in adult animals. Body weight (Bwt) was positively correlated with EA dose (mg) and an optimal EA dose can be calculated.
authors.affiliation: a Department of Otorhinolaryngology , Kyungpook National University College of Medicine , Daegu , Korea ;
authors.forename: Jeong Hun
authors.initials: JH
authors.lastname: Jang
authors.affiliation: b Department of Otorhinolaryngology , Boramae Medical Center, Seoul Metropolitan Government-Seoul National University , Seoul , Korea ;
authors.forename: Ho Sun
authors.initials: HS
authors.lastname: Lee
authors.affiliation: c Department of Otorhinolarynogology , Seoul National University College of Medicine , Seoul , Korea ;|d Research Center for Sensory Organs, Medical Research Center, Seoul National University College of Medicine , Seoul , Korea.
authors.forename: Seung Ha
authors.initials: SH
authors.lastname: Oh
authors.affiliation: b Department of Otorhinolaryngology , Boramae Medical Center, Seoul Metropolitan Government-Seoul National University , Seoul , Korea ;
authors.forename: Min-Hyun
authors.initials: MH
authors.lastname: Park
mesh_terms: D000818:Animals; D002415:Cats; D003638:Deafness / Q000139:chemically induced* / Q000473:pathology; D004195:Disease Models, Animal; D004976:Ethacrynic Acid; D007612:Kanamycin; D009925:Organ of Corti / Q000473:pathology
chemical_list: D007612:Kanamycin; D004976:Ethacrynic Acid
keywords: Ethacrynic acid; body weight; deafness; kanamycin