PARTIAL HEARING-LOSS IN THE MACAQUE FOLLOWING THE COADMINISTRATION OFKANAMYCIN AND ETHACRYNIC-ACID

Co-administration of kanamycin (KA) with the loop diuretic ethacrynic acid (EA) rapidly produces a profound hearing loss in the cat while ma intaining normal renal function [Xu et al., Hear. Res. 70, 205-215 (19 93)]. In the present paper we have applied this deafening procedure to the old world monkey Macaca fascicularis (macaque). Following the co- administration of KA and EA, the hearing loss in the macaque developed far slower than we observed in the cat. Moreover, unlike the cat, the re was evidence of a partial recovery in the animal's hearing, resulti ng in a bilaterally symmetrical high frequency hearing loss. The exten t of this hearing loss was dependent on the dose of the EA administere d. Finally, the most unexpected result of the present study was the de gree of acute nephrotoxicity experienced by these animals following th e drug administration. The sensitivity of this species to renal failur e restricted the dose of EA that could be safely administered. In conc lusion, the co-administration of KA and EA cannot reliably produce a p rofound hearing loss in the macaque. While it can produce a dose depen dent high frequency hearing loss the animal will also experience acute renal failure that requires careful management.