简介：Itisknownthataminoglycosideantibioticscandamagethevestibularandauditorysensoryepithelia,andtheloopdiureticscanenhancetheototoxiceffectofaminoglycosides.Previousstudiesonthesynergisticeffectofthesetwotypesofdrugshaveusedmice,guineapigsandcats,butnotrats.Theaimofthisstudywastodeterminethissynergisticeffectsinratcochleae.Ratsreceivedintravenousinjectionsofdifferentdosesoffurosemideand/orintramuscularinjectionsofkanamycinsulfate.Auditorybrainstemresponse(ABR),scanningelectronmicroscopy(SEM)andimmunocytochemistrywereusedtodeterminetheeffectsofdrugadministration.Inthegroupreceivingcombinedadministrationoffurosemideandkanamycin,theABRthresholdshowedsignificantelevation3daysafterdrugadministration,greaterthansingledrugadministration.Thehaircellsshowedvariousdegreesofinjuryfromtheapicalturntothebasalturnofthecochleaandfromtheouterhaircellstotheinnerhaircells.Neuronfibersofthehaircellsshowedsignificantloss7daysafterthedrugadministration,butthenumberofspiralgangliadidnotdecreaseandsupportingcellsshowednosignsofinjury.Ourstudysuggestthatcombinedadministrationoffurosemideandkanamycinhasansynergisticototoxiceffect,andcanresultinhaircelllossandhearinglossinrats.