title: The effect of systemic administration of desmopressin on cochlear function in guinea pigs.
abstract: CONCLUSIONS
  Systemic desmopressin (dDAVP) administration in guinea pigs for up to 2 weeks induced only minor or no significant changes in cochlear sensitivity, suggesting that other factors may be required to induce the cochlear dysfunction that is usually associated with endolymphatic hydrops.
  
  
  OBJECTIVE
  To investigate the effects of chronic systemic administration of dDAVP, a synthetic analog of vasopressin, on cochlear sensitivity in guinea pigs.
  
  
  METHODS
  dDAVP was administered subcutaneously via a mini-osmotic pump, at a rate of 0.2 ng/kg/min (low-dose group) or 2.0 ng/kg/min (high-dose group) for up to 2 weeks. Cochlear responses (compound action potentials) and distortion product otoacoustic emissions (DPOAEs) were measured. Example specimens were scanned using X-ray micro-tomography (micro-CT).
  
  
  RESULTS
  Compared with the control group, the low-dose dDAVP group showed a significant threshold increase in response to a 2 kHz tone-burst after 2 weeks of treatment, and also a decrease in the amplitude of the DPOAE after 1 week of treatment. However, individual results were variable and the high-dose dDAVP group showed no significant change compared to the control group. In the micro-CT images, two of four ears in the low-dose group showed mild hydrops, but no hydrops was found in the three ears sampled from the high-dose group.
authors.affiliation: Brain & Mind Research Institute, Sydney Medical School, University of Sydney, New South Wales, Australia.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Chihara
authors.forename: Christopher
authors.initials: C
authors.lastname: Wong
authors.forename: Ian S
authors.initials: IS
authors.lastname: Curthoys
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Brown
mesh_terms: D000818:Animals; D001309:Auditory Threshold / Q000187:drug effects*; D003051:Cochlea / Q000187:drug effects* / Q000502:physiology; D003894:Deamino Arginine Vasopressin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006168:Guinea Pigs; D007279:Injections, Subcutaneous; D008297:Male; D023421:Models, Animal; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*; D011897:Random Allocation; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D003894:Deamino Arginine Vasopressin