PROTECTION AGAINST AMINOGYCOSIDE OTIC DROP-INDUCED OTOTOXICITY BY A SPIN TRAP(PBN): CHRONIC EFFECTS
1Ankara Numune Hastanesi, 1.KBB, Ankara, Türkiye2The University of Kentucky College of Medicine, Otolaryngology Head and Neck Surgery, Kentucky, ABD Objectives: To investigated the long-term spin trap protection against aminoglycoside otic drop-induced ototoxicity.
Material and Methods: We evaluated the ability of intraperitoneal α-phenyl-tert-butyl-nitrone (PBN) or 0.9% saline applications to reduce the chronic effects of topical aminoglycoside otic drops (AD) or artificial perilymph (PER) treatment on cochlear microphonic (CM), compound action potential (CAP) and 2F1-F2 distortion product otoacoustic emission (DPOAEs) sensitivities in three groups of guinea pigs. (n=5/group): a) saline+PER (controls), b) saline+AD and c) PBN+AD.
Results: Relative to control values, saline+AD group mean CM and CAP values were severely degraded at all frequencies (p<.05). PBN+AD group mean losses were significantly (p<.05) smaller than those of the saline+AD group for CAP and CM at 8, 12, 16 and 24 kHz, indicating that PBN provided protection against topical AD induced damage. Mean 2F1-F2 DPOAE values decreased to below background levels at all frequencies in groups receiving ADs, irrespective of PBN treatment.
Conclusion: These findings suggest that free radical mediated events are partially responsible for, and that DPOAEs are very sensitive to, AD induced chronic ototoxicity in guinea pigs.
Keywords : otoacoustic emissions, ototoxicity, PBN