Objective:The experiment was designed to study the antagonistic effects of oxytocin (OXT) to the ototoxicity of amikacin
(AK) in outer hair cells (OHC) in vitro .Method:OHC mobility was continuously monitored by video camera system and the contents of
intracellular free calcium(
i) in OHC were determined by fluorescent indicators Fura-2.Results:(1)No obvious effects of OXT on i and mobility ( P >0.05) were detected in normal OHC.(2)Application of AK at the concentration of 3.23 mg·ml 1 led to a sharp decrease in contents of i,AK at the concentration of 6.67 mg· ml 1 resulted in a shrink and invagination of the cell membrane of OHC.In turn,the OHC decreased partly in diameter.(3)When 0.91 IU·ml 1 of OXT was applied after administration of amikacin,the contents of i in OHC were unaffected within 30s,but 1.25 IU·ml 1 of OXT resulted in an obvious restoration of morphology of the OHC after 2 min.Preconditioned with OXT,AK at the same concentration led to a light decrease in contents of i and a light change in morphology of OHC.Conclusion:OXT prevents from and impair the ototoxicity of AK on isolated OHC.