title: [Effects of sildenafil citrate on mice hearing].
abstract: OBJECTIVE
  The purpose of this investigation was to study the effects of the Sildenafil citrate on mice hearing.
  
  
  METHODS
  Seven-week-old adult male Kunming mice were used. The mice were randomly divided into four groups with 10 mice in each group.Sildenafil groups were orally administered daily with sildenafil [0.1 mg/(kg·d), 1 mg/(kg·d), 10 mg/(kg·d)] and control group was orally administered with normal saline. Then mice were tested for auditory brainstem response (ABR) to observe the changes of ABR's thresholds at before administration and 1, 5, 10, 15, 20 day afterwards. The mice basilar membrane samples were studied by immunofluorescent labeling.High performance liquid chromatography was used for determination the concentration of sildenafil in endolymph of mice cochlea. Statistical analysis was performed using SPSS 13.0.
  
  
  RESULTS
  After 30 min following administration, the Sildenafil in endolymph of mice cochlear could be assayed by high performance liquid chromatography, and it was dose-related.Sildenafil increased the hearing thresholds with the time of administration. Hearing thresholds increased significantly in the sildenafil group at 20 d compared to the control group (P < 0.05). After administered high dose of Sildenafil, on the 20th day, the ABR thresholds average threshold was (60.0 ± 10.0) dBnHL, and the control group was (14.5 ± 6.0) dBnHL.Hair cells damages in the base ring of cochlea could be observed in experimental group in a concentration-dependent manner.
  
  
  CONCLUSIONS
  Sildenafil can pass through blood-labyrinth barrier to the inner ear, and doses of sildenafil administration can induce hearing impairment in mice.
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Southwest Hospital of the Third Military Medical University, Chongqing 400038, China.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Luo
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Southwest Hospital of the Third Military Medical University, Chongqing 400038, China.
authors.forename: Xuyao
authors.initials: X
authors.lastname: Guo
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Southwest Hospital of the Third Military Medical University, Chongqing 400038, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Southwest Hospital of the Third Military Medical University, Chongqing 400038, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Southwest Hospital of the Third Military Medical University, Chongqing 400038, China.
authors.forename: Xueyuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Otorhinolaryngology Head and Neck Surgery, Southwest Hospital of the Third Military Medical University, Chongqing 400038, China. Email:weiyuan175@sina.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
mesh_terms: D000818:Animals; D003051:Cochlea / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D007758:Ear, Inner; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects*; D006320:Hearing Tests; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D011687:Purines / Q000008:administration & dosage / Q000494:pharmacology; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D000068677:Sildenafil Citrate