title: Protective effect of propofol on noise-induced hearing loss.
abstract: Iatrogenic noise produced by mastoid or craniotomy drills may cause hearing damage, which is induced by the generation of reactive oxygen species (ROS) and the reduction of cochlear blood flow (CoBF). This study investigated whether propofol could reduce noise-induced hearing loss (NIHL) in a guinea pig model.
  
  
  
  Sixty-four male pigmented guinea pigs were randomly and equally divided into 4 groups: control, noise, propofol and propofol+noise. Propofol was infused intravenously for 20min prior to noise exposure with a loading dose of 5mg·kg-1for 5min and a maintenance infusion of 20mg·kg-1·h-1for 135min. For noise exposure, an octave band noise at a 124dB sound pressure level (SPL) was administered to animals for 2h. The mean arterial pressure (MAP) and CoBF were monitored continuously. Auditory function was measured by the level of distortion product otoacoustic emission (DPOAE) before and at 1h, 72h and 240h after noise exposure. Cochlear levels of 8-iso-Prostaglandin F2alpha(8-iso-PGF2α) were measured immediately after the termination of noise exposure. Cochlear silver nitrate staining and outer hair cell (OHC) counting were performed after the final functional test.
  
  
  
  Noise exposure caused decreases in the CoBF and DPOAE amplitudes, over-generation of 8-iso-PGF2α and the loss of OHCs. Pre-treatment with propofol significantly increased the CoBF and DPOAE amplitudes, decreased 8-iso-PGF2α and the loss of OHCs.
  
  
  
  Propofol exerted protective effects against NIHL in this animal model by suppressing a lipid peroxidation reaction and improving CoBF.
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, PR China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wen
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Duan
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, PR China.
authors.forename: Gui-Xia
authors.initials: GX
authors.lastname: Jing
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital of Xi'an Jiaotong University, PR China. Electronic address: xiaoying_0007@163.cm.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xiao
mesh_terms: D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002452:Cell Count; D003051:Cochlea / Q000098:blood supply / Q000187:drug effects / Q000473:pathology; D015237:Dinoprost / Q000031:analogs & derivatives / Q000378:metabolism; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D006168:Guinea Pigs; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects / Q000473:pathology; D006317:Hearing Loss, Noise-Induced / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D007262:Infusions, Intravenous; D008297:Male; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009622:Noise; D015742:Propofol / Q000494:pharmacology*; D011897:Random Allocation; D012039:Regional Blood Flow / Q000187:drug effects; D012835:Silver Nitrate
chemical_list: D018696:Neuroprotective Agents; C075750:8-epi-prostaglandin F2alpha; D012835:Silver Nitrate; D015237:Dinoprost; D015742:Propofol
keywords: 8-iso-PGF2α; Cochlear blood flow; Noise-induced hearing loss; Propofol