Abstract
Effects of 3', 4'-dideoxykanamycin B (DKB) on the auditory function of guinea pigs were examined by means of PREYER'S pinna reflex method and the evaluation of maximum cochlear microphonics (CM).
Complete loss of the pinna reflex and scarcely visible CM were taken about two weeks in each group of animals given daily dose of 200mg/kg (as base activity) of DKB and 100mg/kgof comparative drug, gentamicin sulfate (GM). It took approximately three weeks to lose the pinna reflex of the animals dosed with 150mg/kg of DKB 80mg/kg of GM, and then remarkably decreased CM was also observed in these groups. There was no change on the reflex of the animals treated with DKB at the dose of 100mg/kg and 50mg/kg for two months, in the former group, however, CM was slightly reduced in the ampitudes, which may indicate that limited injuries were presented in their cochleas. The animals given daily 60mg/kg of GM lost the reflex until four weeks but two in this group, and yet some of them remained the heighest potential in the animals that missed the movement of the pinna.
Based on the mg/kg dosage of the antibiotics, number of days to take abolishing the reflex and the estimation of CM, it was suggested that DKB was nearly a half as auditory toxic as GM.
