The possible protective role of aminoguanidine in gentamicin-induced ototoxicity in guinea pig: A histological and immunohistochemical study

Abstract

INTRODUCTION: Gentamicin is an ototoxic drug affecting both auditory and vestibular cells. Reactive oxygen species might play important role in the molecular pathway of this ototoxicity. Aminoguanidine is one of the guanidine derivatives and is considered as an antioxidant therapy. AIM OF THE WORK: to investigate the possible protective effect of aminoguanidine on ototoxicity induced by gentamicin in guinea pig. MATERIALS AND METHODS: Twenty one adult male guinea pigs were used. They were divided into three groups, seven animals each. Group I: served as a control group. Group II: I.M. injection of gentamicin (80 mg/kg/day) was used for 14 days. Group III: animals received gentamicin in the same way as group II and then followed by aminoguanidine (100 mg/kg/ day) administration using a gastric tube for 14 days. At the end of experiment, the cochlea was excised and prepared for light (LM) and scanning electron microscope (SME) examination. Immunohistochemichal technique was done to detect iNOS. Morphometric and statistical studies were also done. RESULTS: By LM and SME examination, the present study showed that aminoguanidine protected the structure of organ of Corti in the cochlea by decreasing the degeneration of hair cells and other supporting cells. It also showed a significant decrease in the iNOS immune-reactivity in organ of Corti, stria vascularis and bipolar cells in spiral ganglia compared to group II. CONCLUSION: Aminoguanidine is a promising and successful antioxidant therapy for ototoxicity. © 2013 The Egyptian Journal of Histology.