The Effect of Memantine on Experimentally Gentamicin Induced Vestibulotoxicity in Guinea Pigs / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: In general, aminoglycosides are known to cause ototoxicity through the glutamate induced nitric oxide production. The N-methyl-D-aspartate (NMDA) related glutamate receptors have a pivotal role in aminoglycoside induced ototoxicity. Memantine is known as a safe NMDA antagonist and is also used in some neurologic insults, such as the Alzheimer disease. In this study, we observed the effect of memantine on gentamicin induced vestibulotoxicity in an animal model. MATERIALS AND METHOD: Vestibulotoxicity was induced with intratympanic administration of gentamicin and memantine was injected intraperitoneally to a study group. Histomorphological studies for vestibule were performed via light and electron microscopy. Immunohistochemical studies were performed for iNOS, nitrotyrosine and apoptosis via TUNEL staining. RESULTS: The numbers of hair cells were decreased significantly in the gentamicin group than in the gentamicin-memantine group. Increased immunoreactivities for iNOS and nitrotyrosine were observed in the gentamicin group than in the memantine-pretreated gentamicin group. TUNEL positive cells were more frequently observed in the gentamicin group than in the memantinepretreated gentamicin group. CONCLUSION: This result shows that memantine has a protection effect on gentamicin-induced vestibulotoxicity in an animal model.