Experimental Study Of The Conditional Ototoxicity Of Penicillin

Objective:(1)To observe changs of the distortion product otoacoustic emissions and hair cells induced by penicillin in iron-deficient rats. (2) To study the relation between abnormality of distortion product otoacoustic emissions and damage of hair cells induced by penicillin in iron-deficient rats.Methods: Sixty-four healthy Wistar rats were randomly divided into 4 groups. The animals of group A,B were fed with standard diet .In Group C,D, the rats were given the basic iron-deficent diet for 4 weeks .The rats of group B,D were received intraperitoneal injection of penicillin for 14 days.The DPOAE audiogram were measured and the changs of hair cells were observed by scanning electron microscope at 1 and 15 days after administration.Results: The amplitudes of DPOAE in normal rats induced by penicillin is stable。The scaning electron microscope showed no signs of damages of the inner and outer hair cells。The amplitudes of DPOAE in iron-deficient rats induced by penicillin decreased significantly in 0.7~8KHz frequency (p < 0.05). The scanning electron microscope showed stereocilia of the outer and inner hair cells were disarrangment and some disappeared at middle,apical and basal cochlear turns. Conclusion: The results suggest that penicillin have no ototoxicity to normal rats but may have potential effect on the function and structure of cochlear hair cells when iron deficiency exists.The damages of inner and outer hair cells first appear at middle cochlear turns and then extend to the apical and basal turns...