title: Effect of erythropoietin on acoustically traumatized rat cochlea: an immunohistochemical study.
abstract: OBJECTIVE
  To investigate the audiological and histopathological effects of erythropoietin on acoustic overstimulation in rats.
  
  
  METHODS
  Twenty-two male Wistar albino rats were divided into 3 groups: sham group (n = 7), erythropoietin injection group (n = 8), and saline injection group (n = 7). Both erythropoietin and saline injection groups were exposed to white noise (100 decibel [dB] sound pressure level [SPL]) for 3 hours. Auditory brainstem responses were measured before, immediately after, and on the 7th day of noise exposure. All animals were sacrificed on the 7th day and temporal bones were collected. The serial sections of the cochleae were stained by caspase-3 and caspase-9 immunostaining and by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method in order to detect apoptotic cells.
  
  
  RESULTS
  In the saline group statistically significant differences were detected between the baseline and immediate postacoustic overstimulation thresholds of click and 6 kHz stimuli. However, when the baseline and immediate postacoustic overstimulation thresholds of click and 6 kHz stimuli were compared in the erythropoietin injection group, no statistically significant difference was determined. Histopathologic evaluations demonstrated that erythropoietin decreased the amount of apoptotic cells in the cochlea.
  
  
  CONCLUSIONS
  Erythropoietin is likely to prevent the acute threshold changes and decrease the amount of apoptosis in cochlea after acoustic overstimulation in rats.
authors.forename: Oğuzhan
authors.initials: O
authors.lastname: Gürgen
authors.forename: Seren Gülşen
authors.initials: SG
authors.lastname: Gürgen
authors.forename: Günay
authors.initials: G
authors.lastname: Kirkim
authors.forename: Efsun
authors.initials: E
authors.lastname: Kolatan
authors.forename: Selhan
authors.initials: S
authors.lastname: Gürkan
authors.forename: Yeşim
authors.initials: Y
authors.lastname: Güvenç
authors.forename: Görkem
authors.initials: G
authors.lastname: Eskiizmir
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D003051:Cochlea / Q000187:drug effects / Q000293:injuries*; D004921:Erythropoietin / Q000008:administration & dosage*; D016057:Evoked Potentials, Auditory, Brain Stem; D006317:Hearing Loss, Noise-Induced / Q000188:drug therapy / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D051381:Rats
chemical_list: D004921:Erythropoietin